Abstract:    As an important link between finance and ecological environment, green finance can effectively serve the green technological innovation and it is an important issue in the process of promoting the coordinated development of economy, society and ecological environment. Under the dual background of building a green financial system and a market-oriented green technology innovation system, it is of great significance to analyze how the issuance of green bonds plays a role in corporate green technology innovation, with green bonds as the breakthrough point, the promotion of green technology innovation quality increment as the central point, and the research on the "color" of China′s green bond market as the focus of attention.Taking the A-share listed companies in Shanghai and Shenzhen stock exchanges of China from 2010 to 2019 as the research sample, and adopting the theory of green bond issuance to promote the quality improvement of green technology innovation, this paper used the PSM-DID model to conduct a systematic analysis on the relationship between green bond issuance and corporate green technology innovation, their action mechanism and heterogeneous impact, deconstructed the internal logic of green bond and corporate green technology innovation, and used multiple robustness tests to verify the reliability of the research results.The results showed that: (1) the issuance of green bonds is helpful to improve the quality of green technological innovation of enterprises; (2) the higher the issuing amount and the longer the issuing period of green bonds, the stronger the promotion effect on the green technological innovation ability of enterprises; (3) the test of action path showed that enterprises issuing green bonds can act on the green technological innovation of enterprises through three paths: increasing the investment in research and development, reducing the financing cost of enterprises and increasing the attention of investors; and (4) the test results based on corporate heterogeneity showed that the promotion effect of green bond issuance on corporate green technology innovation is more obvious in non-state-owned enterprises and the western region sample.The research results will theoretically enrich the relevant research on the economic consequences of corporate green debt financing and the influencing factors of corporate green technology innovation, and thus practically provide not only policy references for "building a green financial system" and "building a market-oriented green technology innovation system" in the process of high-quality development in China, but also empirical evidence for decision-making departments and the public to judge the "color" of the current Chinese green bond market and prevent the risk of "greenwashing" of green bonds.

Key words: green bond, green technological innovation, R&D investment, financing cost, investor concern