Abstract:To understand the natural regeneration of Cyclobananopsis chungii nature forest, seed rain and soil seed bank of a C. chungii forest in Minqing C. chungii Forest Nature Reserve were investigated. The results showed that seed rain continued about two months with an average of 12.44 seeds m-2 and peaked at late November to early December. There’s significant difference among the proportions of perfect, worm-eaten, abortive, decayed and germinated seeds in the process of seed rain, in which the proportion of the worm-eaten was 19.44 times as great as the geminated. In the soil seed bank, the proportion of the worm-eaten seed was 53.79%. Compared with the seed rain, the quantities of the perfect and geminated seed were less 2.15 seeds m-2 and 0.20 seeds m-2 respectively. Seed survival rate and the proportion of seed damaged by animals were 13.51% and 45.90%, respectively, which showed that animal damage was the main cause of seed loss. In total, 69 species of seeds were recorded in the soil seed bank, with a very low density of germinable seeds and most of them were buried in 2~5 cm in soil. Seedling density of C. chungii was very low in the nature forest, which was closely related to the seed characteristics and habitat. Due to the animal invasion, rotten, abortion, and so on, it’s difficult for C. chungii mature seed to long-term preserve in the soil, and the natural regeneration of C. chungii forest was blocked seriously.