Interspecific competition is one of major forces which determine community structures. Competition results sometimes depend on physical conditions, such as temperature. However, it has not been understood well how the changes in physical conditions alter species superiority in competition. Recent studies have revealed the importance of reproductive interference as determinant of competition results. Here reproductive interference is any negative interspecific interaction in reproductive process caused by incomplete species recognition. As temperature can affect behaviors of ectotherms, changes in temperature may alter the intensity of reproductive interference, and in turn alter competition results between species. Between Callosobruchus chinensis and C. maculatus, males of C. chinensis asymmetrically reduce fecundity of C. maculatus, and the reproductive interference governs competition results, at least at 30°C. In this study, we investigate the effect of temperature on the intensity of reproductive interference from C. chinensis on C. maculatus. Based on the results, we discuss the biological mechanism in which changes in temperature alter competition results.