1. Eight kinds of forage crops, that are four grasses and four legumes, were reseeded in the natural grassland, to determine the yield of each forage crop and to evaluate the effect of competition between those crops, in 1960 and 1961. 2. In the first year, the yields of Orchard grass and Perennial ryegrass and Reed cana grass were abandant, whereas Ladino clover and Alfalfa showed poor yield Generally the yield of grasses was higher than that of legumes. 3. The yield of wild grasses in the legume crop plots was increased more than that in the grass crop plots during the first year. 4. In the second year, the yield of Red clover and Orchard grass was high, whereas Alfalfa, Perennial ryegrass and Sericea lespedeza showed low yield. 5. The yield of wild grass in the legume crop plots was higher than the grass crop plots in the second year. The above result suggested that the nitrogen content of legume crop plot soil was increased by the nitrogen fixation of legume crops. 6. The comparison of forage yields in the second year with that in the first year shows as follows. a). The yields of legumes showed much higher increasing ratios than grasses. Especially, Ladino clover yielded two hundred and eight times of the first year in the plots of the second year. It will show much increasing ratio in the succeeding year. b). Red clover, Ladino clover and Orchard grass among eight kinds of forage crops seem to be suitable kinds of forage crops for reseeding in the natural grassland.