Achieving economies of scale or scope through scaling up is one of the key pursuits of company operation and development. China's chemical companies are embracing a period of change due to the global economic recovery, lower financing costs, and national regulatory policies on national security and environmental protection. With increasingly stringent regulatory policies, China's chemical industry sees different competitive dynamics. Some chemical companies are facing the risk of being eliminated due to their small scale and low technical level, and their production processes are difficult to meet national environmental protection standards. On the contrary, high-quality enterprises can achieve development through capital increase, expansion, mergers and acquisitions (M&A), etc. However, the M&A of China's chemical industry enterprises are becoming more and more frequent. These activities show new characteristics and bring new opportunities and challenges. Scholars have not reached a consensus on whether M&A
can improve the performance of the acquiring companies.

Based on the above background, the research content and the problems that this thesis tries to solve mainly include the following three aspects. First, the thesis analyses and empirically tests the impact of M&A on performance in China's chemical industry, and considers the heterogeneity of the impact in the dimensions of industry, year, and corporate characteristics, and analyses the moderating effect of enterprise and industry characteristics on the relationship between M&A and performance. Second, the thesis analyses the current M&A situation of Chinese state-owned enterprises and private enterprises, and empirically tests the impact of
corporate ownership structure on M&A performance, combined with the pesticide industry the author is engaged in, I select three typical pesticide listed companies' M&A events for case study. Third, the thesis analyses the influence of regional policy intensity and institutional environment on the relationship between M&A and performance at the macro level, including the degree of
marketisation, the level of intellectual property protection, the intensity of chemical industry policies, and the layout of chemical parks in different provinces in China.

There are four main conclusions of this thesis. First, the M&A activities of listed companies have positive impact on performance in the chemical industry, but there is significant heterogeneity. From the perspective of sub-sectors, M&A in synthetic fibre, commodity chemicals, and diversified chemicals have greater positive impact on performance, from the perspective of M&A time, the positive impact of M&A is more significant in recent years. Second, from the moderating effect of corporate and industry characteristics, the impact of M&A on performance is positively moderated by corporate R&D investment and social responsibility, indicating that
with the increase of enterprise R&D investment and social responsibility, the positive impact of M&A on performance will be strengthened. In addition, the higher the average age and tenure of the senior management team, the less conducive to M&A performance, the higher the average level of education, the better the performance of M&A. Third, the impact of state-owned
enterprises’ M&A on performance is significantly positive, and the M&A performance of local state-owned enterprises is better than that of central state-owned enterprises, while the impact of private enterprises’ M&A on performance is not significant, indicating that the local state-owned ownership structure is more conducive to the improvement of M&A performance. Fourth, from the perspective of the moderating effect of regional policies and institutional factors at the macro level, for listed companies in the synthetic fibre and industrial gases industries, the impact of M&A on performance is positively moderated by the regional institutional environment. For listed companies in commodity chemicals and specialty chemicals industries, the impact of M&A on performance is positively moderated by policy intensity, that is, with the increase of policy intensity, the positive impact of M&A on performance will be strengthened.

The marginal contributions of this thesis include the following three. First, from the novel perspective of heterogeneity effect, the thesis empirically analyses the relationship between M&A and performance at different dimensions. Second, the thesis analyses the characteristics of China's state-owned enterprises and private enterprises, as well as the current M&A situation of enterprises with different ownerships, and empirically tests the impact of enterprise ownership structure on M&A performance. Third, the thesis discusses the impact of regional macro characteristics on the relationship between M&A and performance from four perspectives:
regional market environment, intellectual property protection level, chemical industry policy intensity, and the number of chemical parks.