Since reforms in 1978，the central government's rural policies experience adjustments many times，but stabilizing and improving the double management system has been always the theme of rural economic system reform.The key point of rural policies at present is to provide socialized services for the household production of small-scale peasants，so as to strengthen the “integrating” function of the double management system.Peasants' professional cooperatives are the special organizations both are enterprises and communities，which see the peasants as main body，and servicing members as the purpose，have many advantages such as being from rural grassroots，familiar with peasants' preferences，and reducing transaction costs.Therefore，the cooperatives would be the important operators to provide series of socialized services to small-scale peasants，we should focus on their positions and functions in the new round rural reform.At the same time，along with the strategic objectives of “establishing and perfecting the basic public services system，to promote equal basic public services” have been written into the 12th five-year plan，how to build rural public services multivariate supply mechanism including cooperatives，become the focus of the academic circles.Under this background，to research the services function and efficiency of cooperatives has important theoretical and practical significances.

However，although cooperatives' quantities are growing rapidly in China，but which quality has a concern，and cooperatives' governance has a variety of chaos：in order to obtain all kinds of policies benefits，many false cooperatives which have no business entity take turns to play，a few members control cooperative，big-scale peasants “eating” small-scale peasants，such phenomenon exist for a long time.Many problems make cooperatives can't play the role of peasants' spokesman effectively to connect the small-scale peasants and the big market.Relevant debates about cooperatives point to a same question：how cooperatives provide superior and efficient services for peasants？

According to the above problems，based on the basic theories of public services，the paper discusses the decomposition of efficiency，and analysis public services efficiency of cooperatives layer by layer from regional perspective，membership perspective and organizational perspective.

From the tool efficiency of regional perspective，the results show that：

Regional cooperatives evaluation index system of public services efficiency can be constructed through three aspects indicators，including management services，business services and demonstration services.This evaluation system can be used as important reference standard to assess development level of cooperatives' demonstration area.Regional overall level of cooperatives' public service efficiency in Zhejiang province is low，and unbalanced，which has large room to improve.Regional cooperatives' public services efficiency level has no significant relationship with the regional economic development level.

From the value efficiency of membership perspective，the results show that：

First，cooperatives' public services show the structural imbalance between supply and demand，however，the overall satisfaction is higher to small and medium-sized members，the results reflect the typical features of cooperatives in the initial stage of development：most part-time small-scale peasants have low dependence degree to cooperatives' public service，and take limited participation to management and low interests involved to the cooperatives.

Second，the cooperatives initiated by government departments，their public services efficiency is higher；Direct service process，including service diversification degree，financial openness，operation and management，democratic participation and the training frequency，etc.，has a critical positive impact to public services efficiency of cooperatives.The social services functions such as enhancing trust among peasants and promoting the communication between the government and peasants have higher efficiency than the economic services functions such as increasing income and improving the industrial scale.Therefore，the cooperatives initiated by government departments should play the role of demonstration，and the cooperatives' public services process should been keep open to small and medium-sized memberships；cooperatives' function of social integration for small and medium-sized memberships should been pay more attention.

From the comprehensive efficiency of organizational perspective，the results show that：

First，individual cooperative evaluation index system of public services efficiency can be constructed through four aspects indicators，including operation and management，membership services，community services and social impact.Cooperatives in Zhejiang province showed lower overall levels of public services efficiency，the results have not confirmed that the higher the grade，the higher the efficiency.Provincial-level demonstration cooperatives have higher external efficiency，while county-level demonstration cooperatives have higher value efficiency.

Second，from the effect factors of public services efficiency of cooperatives，the cooperatives initiated by government departments and village cadres，which public services efficiency is lower than the cooperatives initiated by small-scale peasants.“Membership supervision” has more direct positive effect to public services efficiency of cooperatives.“Product certification”，“demonstration level”，“member satisfaction” and “government support” such environmental factors have significant positive effects on cooperatives' efficiency.

Third，the government's support promote more to the public services external efficiency and tool efficiency of cooperatives，but less to the public services internal efficiency and value efficiency of cooperatives.In other words，the government's support effects mainly have been reflected in the external economic effects on market level，but not the internal social effects on membership level.

Finally，based on above analysis，the paper puts forward following countermeasures：

First，the governments should play full role in cooperatives' formal system supply.On one hand，empower cooperatives higher strategic position through legal and policy means in the field of “agriculture，rural areas and peasants”；On the other hand，play the role of planners and public services “gatekeeper”，to create a good economic and social environments for cooperatives and agricultural enterprises，social organizations，and other related benefit main body to compete and cooperate in the market.

Second，the governments' policy guidance on cooperatives should be “peasants development priority in agricultural development” and “the value efficiency first，then the tool efficiency”.The government should do good job on peasants members' empowerment and rights protection，take measures to promote institutional construction on peasants members' training and education，see the development of peasants as the center，so as to lay the foundation for sustainable growth of cooperatives；and the government should pay attention to services demand of most part-time small-scale peasants，put the related “membership evaluation indicators” in the current evaluation index system on demonstration cooperatives，support the cooperatives to meet services requirements of small and medium-sized membership and enhance the abilities of creating public values，while make necessary constraints on the departments' interests and capital interests in the countryside.

Third，the central government carries out the reform pilot work on cooperatives' association and regional comprehensive cooperatives，and attaches great importance to the social integration functions of cooperatives on servicing small and medium-sized membership.In the process of policies making and perfecting，the government should pay attention to guidance，support and foster cooperatives to play more active roles to reconstruct rural public space for small-scale atomized peasants and strengthen the communication link between the country and peasants.

Fourth，according to the special “double multi-layers” principal-agent relationship of China's cooperatives，the paper proposes to establish multiple incentive strategies for the optimization of cooperatives' public services efficiency by the way of formal system as dominant，informal system as supplement.，the specific measures including：the regulation incentives on the basis of government lead，the “accountability” incentives on the basis of empowerment to small and medium-sized members，the “reputation” incentives on the basis of cooperatives autonomy，the long-term contracts incentives on the basis of multi-bodies collaboration.

Fifth，in the process of formulating cooperatives policy，the government departments should focus on the regional characteristics of public services efficiency of cooperatives，give full consideration to the regional differences and imbalance on cooperatives development base，agricultural industrial cluster and social cultural environments and find a balance between the central policies and the regional policies，attention that policy implementation is not “one size fits all”.At the same time，the government focus on the positive role of the informal norms such as culture，customs and habits in the cooperatives governance，pay attention to combine with the positive and reasonable factors in local informal norms in the process of regulation construction of cooperatives.

On the basis of reference to previous research，the paper conducts a creative exploration from the following several aspects：

First of all，the past research of cooperatives' efficiency has the tendency of “paying attention to management，but ignoring services”，the paper specializes in “public service efficiency” of cooperatives from the Club Products Theory，enrich the research perspectives of the cooperatives' efficiency.The study emphasizes that the cooperative has both enterprise and community organization characteristics，cooperative is a kind of club organization，its purpose is to serving for membership.All of its business activities are in order to let members enjoy high-quality public services，so the cooperatives' efficiency should be seen as efficiency of public services.

Second，the paper combines the concept of “efficiency” in economics and the concept of “efficiency” in management，proposes the cooperatives' “comprehensive efficiency” concept of public service firstly.The comprehensive efficiency can be decomposed into “tool efficiency” and “value efficiency” from the angle of the goal orientation of efficiency，and decomposed into internal efficiency and external efficiency from the angle of effect scope.And for the first time，the paper explores the different levels and faces about public services efficiency of cooperatives from three aspects of the tool efficiency of regional perspective，the value efficiency of membership perspective，and the comprehensive efficiency of organizational perspective.

Third，the results confirmed some scholars' theoretical judgments to some degree，that's to say，to many part-time small-scale peasants，it's often less important to increase income by cooperatives.Nevertheless，small-scale peasants have the needs to reconstruct village public order，to undertake a top-down transferring resources，to maintain social contacts and get the meaning of life by cooperatives.The results show that social services functions such as enhancing trust among peasants and promoting the communication between the government and peasants have higher efficiency than the economic services functions such as increasing income and improving the industrial scale.Therefore，the small-scale peasants pay more attention to the cooperatives' social integration functions than economic services functions.

Fourth，through the decomposition and comparison of comprehensive efficiency，the paper draws a new conclusion：government's supports promote the cooperatives' external efficiency and tool efficiency more，but promote internal efficiency and value efficiency less.In other words，the promoting effects of government's supports to the development of cooperatives are mainly in the external economic effects in the market level，not obvious in the internal social effects on membership.This conclusion has important inspiration significance to the cooperatives' policy at present.

Key words：Peasants' Professional Cooperatives；Public Services；Tool Efficiency；Value Efficiency；Club Products；Principal-agent Relationship