The aim of this study is to conduct a comparative investigation of investment and manufacturing company's portfolio with an emphasis on market return in firms listed in Tehran Stock Exchange (TSE). Statistical sample of the research includes 14 investment firms and 14 manufacturing companies which are studied during the period of 2005 to 2009. Jensen model is used to calculate exceed return over market. The results indicate that both investment and manufacturing companies obtain higher return than market return. However, the return obtained by investment firms is higher than manufacturing companies indicating that investment firms have better performance than both market return and manufacturing firms.