Abstract: This study deals with the soil seed bank and seed rain of Mallotus paniculatus forest in Xishuangbanna,Yunnan province. The results show that the soil seed bank had a seed storage of 3345±438 seeds, m-2(Mean±SE, n=20) at the end of rainy season and 4555+554 seed s. m-2 at the end of dry season. The annual seed input was 745 seeds, m-2. The peak of seed input, which caused a high seed storage in soil seed bank ,occurred in dry season. This was in correspondence with the period in which the dominant species dispersed their seeds. The dominant species in seed rain also had a large storage in soil seed bank. The forest fragmentation reduced the seed storage in the soil and seed input and resulted in the significantly high proportion of the seeds of pioneer tree species dispersed by birds in the soil seed bank and seed rain as well. The climax species with seeds dispersed by large animals were not able to reach the isolated forest ,whose succession was retarded.