Institutional Change Of China's Stock Market And Investor Behavior Research

China's stock market is the outcome of the reform of SOEs and financial system. It has become an important part of national economy. Investor is one of the most important principal parts in stock market. This paper is based on the model of interaction between institution and behavior. The author analyzes the interaction between the evolution of institution of China's stock market and investors behavior by using the thinking of Behavioral Finance, new institutional economics and sociology.Household is the main capital provider in China's stock market. It also promotes the stock market's development. The investors' selection of financial products decides the development of financial market and its structure's change. The volatility of stock market is probably due to the change of the ability of enterprises' payoff in the future, and it is also probably due to investors behavior. The investors' decision-making is influenced by their defect of cognize , mood , etc. Stock market has endogenesis frangibility. Some behavior character of investors in China's stock market is the same as foreign countries', and some is special, such as excess frequently trades, psychology of relying on policy , etc. The character of investors behavior is due to the stock segmentation and the defect of the manner of administration. Government's behavior and policy make the market frangibility sometimes. The stock segmentation becomes the shackle of the stock market development.But the logic of the evolution of China's stock market institution is not the same as other fields. Government has conflict as a constitutor of common policy or as an owner of state capital. The traditional administration thoughts disturb the reform. The investors have their individual interests. Whether they can accept the reform project restricts the process of the reform and the function of stock market. Thepause of reform is not benefit to the market. On the contrary, the investors lose confidence and leave the market. The function of China's stock market is turbulence. The reality makes clear to all that China's stock market is facing of the hard and necessitous process of the evolutionof institution.