Abstract: Based on data of high-tech enterprises in Zhongguancun Haidian Science Park from 2008 to 2015, Generalized Propensity Score model is used in this paper to describe dynamic effect curve of intensity change of financial support on R&D expenditure of enterprises with different size and ownership, quantify and evaluate implementation effect of financial support on stimulating R&D activity of high-tech enterprises. The results reveal that: For high-tech enterprises with different size, management level, human resources, research capacity and state-owned character all have positive relationship with financial support that enterprises receive; Financial support can effectively improve R&D enthusiasm of high-tech enterprises with different sizes and there are “saturation points” of marginal effects ,the incentive effect on small enterprises is generally larger than large and medium-sized enterprises; To further subdivide enterprises ownership, it can be found that incentive effect of financial support on non-state-owned enterprises is more significant and the influence range is larger. The conclusions provide some policy implications to optimize the allocation of financial resources and promote the development of technology finance.