Abstarct: Recently The Stock Market has been very important because of its role in progress of country. IPO is one of the most important event in capital market. As the IPO has not been matched with the concept of market and potential investors, it could be accompanied by bad and unwanted outcomes. Because the challenges of Capital Assets Pricing Model (CAPM) The Three Factor Fama-Frech Model could indicate most of the return uneven. This research studied the short term and long term of IPO’s returns with the Fama-French approach. In this study the factors such as free-float, dividend, liquidity and leverage has been accompanied with the Fama-French in the period of 1999-2005. The population of reaserch is all the IPOs of this period. The study is applicable and analytical and cause and effect. The gathering approach is librarian and documentary. The multi variable regression methods and catogorial of 30, 120 and 240 days after offering has been used. According the results of regressions, in the 30 days time, with the dependent variable of return in the 95% significant, with the market return(+), market risk(-), dividend(-), leverage(+), liquidity(+), the ratio of book value to market value(-) and free-float percent(+). In the 120 days time, with the dependent variable of return in the 95% significant, with the market return(+), market risk(-), dividend(+), leverage(+), liquidity(-), the ratio of book value to market value(+) and free-float percent(+). In the 240 days time, with the dependent variable of return in the 95% significant, with the market return(-), market risk(-), dividend(-), leverage(+), liquidity(+), the ratio of book value to market value(+) and free-float percent(-).