Famer economy is an entity of production for value-in-use and value depending on the ecosystem involved，and its basic pattern and evolution law is undoubtedly a complex and debatable issue. Following matters are discussed on basis of modern agricultural economy in Manchuria，such as the corresponding symbiotic relationship existed in the pattern of farmer family economy in a specific ecosystem as well as the interactive influence between ecological development，farmers’ management rationality and norms in rural society.

From the aspect of the quantitive change of farmers’ available resources，the ecosystem in which modern Manchurian farmers lived can be divided into three levels of interactive relationship between farmers and natural environment，i.e. environmental ecology，power ecology and technology ecology. By environmental ecology is meant the level that natural environment has a direct influence on farmers economy. The immigrants of modern Manchuria were mostly from its southern neighboring regions such as Shandong Province and Hebei Province，so an order of“the south firstly and the north subsequently”was followed both in time and space during its process of reclamation in modern Manchuria. Ecological pressure emerged in many regions where agricultural reclamation began earlier. First of all，“Man-land relationship”became serious increasingly. Following large influxes of immigrants and rapid natural increase of population，no cultivable land left in the old reclaimed regions，and per capita cultivated land reduced greatly. Secondly，fertility of cultivated lands dropped greatly due to long-term insufficient fertilizing over a period of time of cultivation. Per mu yield kept by the fertility of many farmlands after30-50years’ cultivation was no more than half of that before. Thirdly，Water loss and soil erosion was sped up as the result of massive deforestation，and eventually led to frequent floods and land desertification. By power ecology is meant the following understanding：natural resources are acquired and controlled by power，which interacts with environment under certain circumstances to set up a behavior system of ecological value emphasizing on resource-controlling. The flow of resources in Manchuria seemed to be subject to market mechanism，but，as a matter of fact，it was always controlled by power. The expansion of market mechanism in modern Manchurian countryside was a process that power gradually acquired resources by means of market. It not only relied directly on the dominant means of political power，but also on the recessive means of economic power. The ecological resources of Manchuria was exported gradually through the market controlled by power，and got no necessary compensation. During the continuous expansion of marketization，Manchurian farmers were exploited in terms of resources，and poverty was delivered by power through transmission of resource. As to the development pattern of rural economy in modern Manchuria，the expansion of market mechanism should not only be regarded as a process of farmers’ gaining through selling their farm products，but also as one in which farmers lost their controlling power over resources. Technologyl ecology put emphasis on the interactive process of modern agricultural technology and local environment and resources，in which we should keep track of the probable change of local environment and resource-utilizing efficiency caused by modern technology，and we also should consider to what degree local resources and natural environment adapt or accept the adopted technology. As far as resources are concerned，Manchurian farmers were not able to fundamentally change their resource-utilizing efficiency by importing enough modern technology，and a lot of new machinery imported from abroad were unsuitable to local farming conditions，therefore，it is impossible for Manchurian agriculture，at the time，to go on the track of sound progress by introducing modern technology.

On the whole，the ecological pressure confronted by Manchurian farmers was getting more and more serious as time went on. The issue of subsistence caused by ecological pressure influenced farmers’ behaviorial rationality，making them to organize their economic behavior such as production，marketing and consumption in an entirely different way. In the newly reclaimed regions of Manchuria where a large amount of fertile farmland was possessed per capita，most farms must rely on hired laborers in their operation to overcome unfavorable effect on agricultural production caused by insufficient labor force. Hired laborers were not just play an auxiliary role in local farmer households，they were put in the agricultural production as an ever-ready labor force. Because of labor force scarcity，hired laborers’ wages in the newly reclaimed regions were much higher than that in other regions. In order to reduce the cost of hired laborers，most farmers who managed large-scale farms were inclined to an extensive farming method，such as shallow ploughing，which involved less laborers，reducing frequency of inter-cultivating and weeding，applying less fertilizer both in quantity and frequency. In order to raise labor productivity and realize maximum benefit，factors of production such as hired laborers，farm tools and fertilizer were put extensively into agricultural production. Obviously，the practice showed that farmers spontaneously regulated the input quantity of factors of production to pursue profit motive. As to the selection of crops，the farms that adopted the practice were inclined to do their utmost to grow the crops that can get more benefit in response to the signal of market price，and sell their farm products at the most favorable market price to get more profit. On the whole，the farmers of the newly reclaimed regions in Manchuria were inclined to operate their farms in accordance with market rationality. Following the decline of soil fertility caused by population increase and environment degeneration，the input of labor force in agricultural production changed gradually from scarcity to surplus. The farms relying on hired laborers were replaced gradually by the small farm relying on family laborers in many old reclaimed regions. As the result of increasingly serious man-land relationship，the importance of land productivity to the farmers surpassed gradually that of labor productivity. Factors of production such as labor force were put into agricultural production in a more and more intensive way，and，consequently，deep cultivation，more weeding and frequent fertilizing were adopted to raise yield per mu. Meanwhile，farmer households exited gradually from market under the ecological pressure. The role of farm management in farmer family economy changed gradually from profit-making to farmers’ supplying directly consumed food resource to ensure their maximum safety of subsistence. On the other hand，the farmers had to rely on sideline to obtain money income and to balance family cash flow. The farmers began to substitute family self-supplying grain crops for original cash crops with higher money value. As a result，the commercializing rate of their farm products declined accordingly，and farmers’ operational rationality changed from the subsistence rationality of pursuing profit to that of pursuing food safety.

As for socio-economic relations such as cooperation，tenancy，and debit and credit，there were a set of fixed economic order for dealing with economic activities in rural society. The order adapted themselves to farmers’ behavior of production and consumption，and coexisted with it in rural society. In such a ecological system，a temporarily stable“symbiosis”relationship was actually formed between individual rationality and social system. Therefore，it was inevitable for the change of farming family operation pattern under ecological pressure to have an influence on the economic order which farmers followed.

In the regions where less ecological pressure was faced by farmers operating large-scale farms，the local social relations were characterized by relying on large family or clan cooperation. However，with the increase of family members and the frequent division of a large family，large families underwent gradual disintegration，and eventually formed a“rural community”relation，which depended on mutual benefit and cooperation of small farmer families. Because of the disintegration of farmland possessed by farmers，it was not worthwhile for every farmer family to possess large-sized farm tools or hire laborers，and therefore they had to effectively plan and use their limited resources. Similarly，some farmers consciously enlarged their mutually usable common resources，and provided poor peasants with some assistance in subsistence.

Appropriate changes in the distribution of land ownership and the relationship of debit and credit took place under the ecological pressure. On the one hand，the beneficiaries of the norms made efforts to set up a system of protection for subsistence and reproduction，which can keep existing economic order from collapse due to individual issue of subsistence and make each individual more deeply set its position in accordance with the norms. Land owners would reduce rent when tenants could not afford to it. Capital owners，sometimes，offered an interest-free loan. On the other hand，various classes under the norms were inclined to reduce their loss under ecological pressure by revising original rules，and even tried to transfer the loss to others. It led to the rise of nominal land rent and interest rate. Under the circumstances，both land-renting and lending declined obviously in profitability，large amount of investment on agricultural production began to shift to non-agricultural fields，and eventually led to the emergence of“common social poverty”among small landed farmers.

In the specific ecological system，a relationship of symbiosis between the pattern of farmer operation and the norms of rural society was formed in a specific shape. The relationship of symbiosis in the original ecological system，e.g. farmers’ economic rationality，farmers’ economic behavior and social behavior norms in rural society，was broken in the wake of the changes of ecological pressure. It can be seen that the forms of various elements changed with ecological system，and eventually established a new relationship of symbiosis. A novel explanation for the pattern of farmer economy and economic order in traditional rural society is given from the aspect of ecological pressure.

Key words：Manchuria；Farmer；Ecology；Pressure；Symbiosis；Economic Order