Abstract: Promoting green innovation in manufacturing enterprises is of great significance for China to achieve its "peak carbon dioxide emissions" and "carbon neutrality" goals, as well as for the comprehensive green transformation of the economy and society. Using a sample of manufacturing firms listed on the A-share market from 2010 to 2021, this study employs a multi-period difference-in-differences model constructed based on the implementation of the trading system of Shanghai-Hong Kong and Shenzhen-Hong Kong Stock Connection, and empirically examines the impact of the trading system on green innovation in manufacturing enterprises. The study reveals that the implementation of the trading system not only promotes green innovation in manufacturing firms, but also enhances the quality of such innovation. Mechanism tests indicate that the trading system promotes green innovation in manufacturing firms by alleviating financing constraints and enhancing environmental information disclosure. Heterogeneity analysis suggests that the impact of the trading system on green innovation is greater for privately-owned manufacturing firms and non-heavy-polluting manufacturing firms. The research findings indicate that the opening up of the capital market plays an important role in promoting green economic development and achieving the "dual carbon" targets, providing a theoretical basis for further expanding the opening up of the capital market.

Key words: stock market opening, "Shanghai-Hong Kong" and "Shenzhen-Hong Kong" Stock Connection, green innovation, manufacturing enterprises