Abstract: The study shows that the early and late seed rains of constructive tree species in evergreen broadleaved forest at Chongqing Simian Mountain had no activity.The bigger the seeds of the species and the earlier or later the seeds of the species matured,the higher the proportion of the seed rain damaged by animals.The quantitative variation of seed rain,active seed rain and seed bank did not take place at the same time.At early time, the number of seed banks of Castanopsis fargesii,Lithocarpus glabra,Quercus myrsinrefolia,Castanopsis plasyacantha,Cinamomum subavenium. which own more active seed rain increased by geomitric series.The seed banks of Castanopsis orthacantha and Schima argentea were small,only survived a short time,and did not sprout next year.The quantitative dynamics of seed banks and their increasing or decreasing rates were decided by the proportion damaged by animals,dying speed of seeds and their resistance to pathogens and adverse circumstances,and the state of seed germination.