Abstract:     Enterprise R&D activities are usually divided into three types: basic research, applied research and experimental development research. Among them, basic research and applied research can enhance the core competitiveness and future profitability of enterprises, as well as the main way of national scientific development and technological progress, and experimental development research directly transforms scientific research achievements into new products or applications, producing economic benefits. In contrast, the exploratory research in the basic and application stages has obvious public goods attributes, which has a serious mismatch between private benefits and costs. Moreover, the promotion of total factor productivity of enterprises in the current period is not as good as experimental development investment. Therefore, listed manufacturing enterprises are more willing to invest their capital in the experimental development stage with short R&D cycle and high profit monopoly, which results in serious shortage of investment intensity in basic research and applied research for listed manufacturing enterprises in China. 
    What is the impact of promoting high-quality development of the manufacturing industry and deep integration of the financial industry on different types of R&D investment? Based on the non-parametric quantile model, this paper makes use of the micro-data of manufacturing listed companies during 2008 and 2018 as research samples to explore the nonlinear and heterogeneous impact of financial-industrial integration on different types of R&D investment. 
    And the results are as follows: (1) The impact of financial-industrial integration on different R&D investment represents nonlinear effects, and shows a significant depression effect on the investment in the research stage, while it represents a "N-shaped" nonlinear characteristic on the investment in the experimental development stage. (2) Financial-industrial integration on different types of R&D investment has heterogeneous impact. With the increase of the quantiles, the depression effect on research stage is more obvious, and the promotion effect on experimental development is strengthened continuously, which has an optimal boundary. (3) With the deepening of financial-industrial integration, state-owned enterprises has obvious crowding out effect on R&D investment at the research stage, but it has a promotion effect on R&D investment at the experimental development stage. What′s more, financial-industrial integration of non-state-owned enterprises can improve their R&D level in the research stage, but it is not conducive to the investment of non-state-owned enterprises in the experimental development stage. (4) Generally speaking, the integration of industry and finance has obvious depression effect on R (the intensity of research stage), and obvious promotion effect on D (the intensity of experimental development), and the optimal combination level of industry and finance in research stage is lower than that in experimental development stage. That is to say, the optimal level of financial-industrial integration in the research stage occurs at a lower level of integration between industry and finance, while the optimal level in the experimental development stage occurs at a higher level of integration between industry and finance. The research in this paper shows that when Chinese listed manufacturing enterprises conduct external financing through the way of financial-industrial integration, they should think over different types of R&D investment, and choose a reasonable degree and way of financial-industrial integration which can adapt to their own innovation ability, so as to provide decision-making basis for improving the R&D investment intensity by selecting reasonable external financing methods. 

Key words:  financial-industrial integration, research stage, experimental development stage, nonlinear heterogeneous effect