以2010—2020年402家民营科技企业数据为研究样本，实证分析企业内外资金持有量对政府研发补贴激励效果的影响，进而追本溯源地剖析影响中国民营科技企业研发补贴激励效果的根本原因。结果显示：企业内外资金持有量对研发补贴的激励效果具有双重门槛效应。一方面，内部资金过多或过少均不利于研发补贴发挥激励作用，当企业内部资金水平过高时，研发补贴对企业研发投入的促进作用最弱；另一方面，外部贷款较少的企业，研发补贴激励作用最显著，随着外部贷款水平提高，研发补贴的激励作用逐渐下降，直至不再显著。

Innovation is of strategic importance to promote new changes in the mode of production, tap new drivers of economic growth, and promote high-quality economic development.As the most active economic entity in the national innovation system, private science and technology enterprises are the main force to promote China's innovation-driven development strategy and the strategic adjustment of economic structure.Innovation is the source of power for the development of private science and technology enterprises, but the innovation activity cycle is long with high cost and risk with the need for a large number of continuous research and development capital investment, while most of the private science and technology enterprises are small and medium-sized enterprises with a relative lack of capital.Therefore, the funding problem has become a long-term obstacle to the development of Chinese private technology enterprises innovation, transformation and upgrading shackles.In order to encourage private science and technology enterprises to improve their innovation capability and competitive advantage by increasing R&D investment, the Chinese government has continuously increased financial support in recent years.However, although the government's R&D subsidies continue to increase, the R&D investment of private technology enterprises has not increased significantly, and the incentive effect of subsidies is not ideal.Therefore, how to improve the incentive effect of government R&D subsidy policy and promote the technological innovation of private technology enterprises has important theoretical significance and practical value for promoting the development strategy of an innovation-oriented country.#br#This paper takes the panel data of 402 private science and technology enterprises from 2010 to 2020 as the research sample,and the internal funds and external loans as the threshold variables.It then establishes the threshold regression model to analyze the influence of different internal and external capital holding on the incentive effect of government R&D subsidies.#br#The results show that,firstly, both the internal funds and external loan holding of enterprises have a double threshold effect on the incentive effect of government R&D subsidies.Second, when the enterprise internal capital holding are at the medium level, the incentive effect of government R&D subsidies on enterprise innovation investment is the strongest;When the enterprise's internal cash holdings are at a low level, the R&D subsidies decline.When the enterprise's internal capital holdings are at the highest level, the incentive effect of R&D subsidies is the weakest.Thirdly, when the external loan level of enterprises is low, the government R&D subsidies have the greatest promoting effect on the innovation input of enterprises.With the increase in the external loan level of enterprises, the incentive effect of R&D subsidies will gradually decline.#br#Considering the internal and external capital allocation situation of China's private technology enterprises, this paper studies the influence of different levels of internal and external capital holding on the utilization of R&D subsidies to fundamentally analyze the reasons for the differential incentive effect of government R&D subsidies among different enterprises, so as to improve the incentive effect of government R&D subsidies.Compared with previous similar studies, the possible innovations in this paper are reflected in three aspects.Firstly, on the basis of different situations of internal and external capital allocation among private science and technology enterprises, this paper deeply analyzes the fundamental reasons why R&D subsidies have different incentive effects on the innovation of different private science and technology enterprises, and updates the research perspective of government R&D subsidies.Secondly, the threshold effect model is used to empirically analyze the reasonable range of the innovation incentive effect of government R&D subsidies on enterprises with different levels of internal and external capital holdings, and it provides a more accurate policy direction for the top-level design of R&D subsidies.In addition, hand-screening of R&D subsidies closely related to the innovation of private science and technology enterprises, excluding non-R&D subsidies, has improved the scientific nature and reliability of the research process and conclusions.#br#