Stock market is a complicated system on which the different interest members such as the      government, public company ,the stockbroker , stock exchange , the intermediary agency and the investors play a game of ' g o' chess.The traditional basic or technical analysis that focus o n a certain kind of specific aspect , lacks of micro study for stock market .The status and significance of the stock price fluctuation analysis was explained initially .On the basis of the existing models of stock price fluctuation, technical methods of theory analysis and positive analysis of the market ex change data were adopted to study deeply the price fluctuation of Chinese stock market .A system model o f stock market w as established by the use of economic control theory .Taking aggregative index number of Shanghai and Shenzhen's stock ex change as samples , a quantitative analysis of the fluctuation was made .I t has drawn a conclusion that, to the exclusion of interferential factors of policy , Chinese stock market itself is a stable system .