This study intends to examine the effect of research and development (R&D) expenditure effects on firm value through patent and earing persistence. The patent is the representative intangible asset which objectively indicates a typical product of research and development activities to external parties. If a firm has acquired the patent, it receives amicable evaluation from the market compared to the firm which has not acquired patent. Empirical analysis is performed for non-banking firms (1,860 firm-years) listed on Korean Stock Exchange with December fiscal year-end over 2004-2009. Research results are as follows. First, the multiple pricing of patent acquiring firm and earing persistence increased group showed that they have higher prices than the other groups. Second, the multiple pricing of R&D expenditures of earing persistence increased group showed that they have higher prices than the other group. Third, the R&D expenditures of earing persistence increased group is receiving more friendly evaluation from the stock market than the other group.