An Empirical Study On The Announcement Effect Of Share Capital Segregation Reform Based On Shanghai Stock's 50 Index

China's capital market is a developing market after development of 15 years. The market has undergone fast development during this period, and the share capital segregation reform of listed companies is the most profound reform of the capital market. It solved the institutional bottleneck which had curved the development the capital market for 15 years, constructed the new platform and laid the foundation of the capital market. Many scholars and researchers have made their contribution to the theory development of the reform. It is of special significance to do the empirical research regarding the share capital segregation reform. The dissertation is about to make empirical research about the reform based on those contributions and foreign classical theories, to find the impact of the reform on the market and test the efficiency of the capital market. The share capital segregation reform is unique in our country, the research will help to better understand the importance, necessity, and the design of the mechanism of the reform, and better understand the capital market through the research.The impacts of the reform on the share prices are explored by empirical research using the method of event study. The conclusion is that the impact of the reform on the price of the listed companies is remarkable, and China's capital market has not become semi-efficient market yet and the share price did go down since the benefit of tradable shareholders were losing due to the institution of the game and the imbalance of the party in the game. In the end, some corresponding strategies are proposed according to the discussion of the problems and the analysis of the empirical result.