Many linkage studies have been made since Parnell et al. (1917) reported a linkage in rice. However, the study on linkage variation in rice is few. In this paper, the effect of temperature on recombination in rice was examined. Two markers, Pl and lg, belonging to the second linkage group and three markers, dp_1, C and ws, belonging to the first linkage group were used. From a few day s before meiosis to heading time, F, plants heterozygous for Pl and lg were grown under controlled room of temperatures at 25, 30 and 33℃, and those for dp_1, C and ws at 25 and 33℃. Recombination value was calculated from F_2 segregation. The recombination value between Pl and lg was the highest at 25℃, and the heterogeneity among treatments was significant (Table 1). The values of dp_1-C, C-ws and dp_1-ws were also higher at 25℃ than at 33℃ (Tables 2, 3 and 4). The results disagree with those obtained in other organisms. For example, recombination value is higher at 30℃ than at 25℃ in Drosophila (Stern, 1926), and, in Sphaerocarpus, it is lower at 18℃ than at any other temperature of 10, 26 and 33℃ (Abel, 1963). It may be thought from these facts that the effect of temperature on recombination differs with different species. In order to make clear whether temperature affected crossing-over interference or not, coefficient of coincidence was calculated following relation; y_1+2 = y_1 + y_2 - 2cy_1y_2 where y_1, y_2, and y_1+2 are recombination value of dp_1-C, C-ws and dp_1-ws, respectively, and c is coefficient of coincidence. The value of c was also higher at 25℃ than at 33℃ (Table 5). It may be a noticeable phenomenon with respect to the role of temperature in the variation of recombination.