Abstract: [Objective]Encouraging farmers to expand the growing areas of woody grains and oil seeds plants, improving the production efficiency and thus easing the grain and oil security problem are the main policy objectives of subsidies for woody grain and oil plants. Determining the effects of subsidies for the woody grain and oil plants in the main producing provinces, and constructing a theoretical model to verify the effectiveness of the policy from the perspective of farmers' behavior response can help to explore the effects and the theoretical mechanism of the subsidy policy. These answers can provide a scientific evidence for the development of more targeted and more efficient woody grain and oil plants subsidy policy.[Method]Firstly, based on the investigations and researches, the main contents of the woody grain and oil plants subsidy policy were reviewed. Secondly, surveys by interviews and questionnaires were used to investigate the implementation of subsidy policy and industrial development of woody grain and oil plants in the main producing provinces, and summarize the practical effects of the subsidy policy. On this basis, assuming the woody grain and oil product market as a perfectly competitive market, we construct theoretical models to analyze the effects of the subsidy policy on the market equilibrium, on the production behaviors of different scale of farmers and on the production efficiency respectively. Besides, by distinguishing different scale growers of woody grain and oil plants, we analyze the effects of the implementation of woody grain and oil plants subsidy policy on the production behavior and efficiency for different scale of growers. The results were used to provide economic explanations for the actual effects of the implementation of subsidy policy.[Result]The results show that:1) After the implementation of the woody grain and oil plants subsidy policy, the planting areas have been greatly increased in the main producing provinces. 2) The prices of main woody grain and oil plants such as Chinese chestnut, jujube, walnut, oil-tea camellia have showed a downward trend. 3) The number of new management organizations of woody grain and oil plants have increased, and the planting scale of single household is expanding, which contribute to the obvious scale concentration effect. 4) The one-time funding subsidy form which is mainly linked to the planting areas is difficult to effectively improve the problem of "emphasizing more on planting but not management", which have limited effects in improving the productivity of woody grain and oil plants. 5) In the context of rising agricultural subsidy standards and planting costs, woody grain and oil plants subsidy standards are low and lack of timely adjustment, which will weaken the incentive effects.[Conclusion]1) The subsidies play an important role in expanding planting scales, which show that it is necessary to realize the continuity of subsidies, and the subsidies for improvement of low yield forest should be properly tilted to small-scale farmers. 2) The afforestation subsidies have led to the "emphasizing more on planting but not management" problem, which have limited effects on the improvement of the productivity of woody grain and oil plants. Forestry subsidy policies should be gradually adjusted from afforestation to management. 3) Too high minimum subsidy areas or too low subsidy standard will result in the reduction of planting areas and the loss of welfare of small-scale producers. So it would be useful to expand the source of subsidy funds and to increase the subsidy standard. 4) The production subsidies only linked to the planting areas make the production efficiency of large-scale growers be lower than the small-scale growers. It is necessary to guide moderate scale operation and improve marginal productivity by setting subsidy conditions.

Key words: woody grain and oil plants, subsidy policy, market equilibrium, crowding out effect, production efficiency