The stock price is influenced by many factors. The share ratio in circulation, the size of company, per share earnings and net asset value per share were considered as the important indexes which decide the stock price. Feltham-Ohlson model was expanded, and the empirical result indicates that the share ratio in circulation effects on the stock price negatively and the other three indexes also influence the price largely. In the implementing moment of the reform of dual-class equity structure, the impact of the share ratio in circulation to stock price, to provide reference for the listed companies to make their financial policies was studied, for the investors to make their reasonable decisions, for the short-term investors to make sensible choice from the aspect of negotiability.