Abstract:Dynamics of the seed bank of Cyclobalanopsis glaucoides was studied with random sampling and burying seeds in C.glaucoides forest on the Xishan Mountain in Kunming.Insects laid their eggs inside young seeds,When eggs developed into worms,they ate inside seeds and caused 71.8% of seed bank above ground to lose their germination power.Most of seeds in the seed band above ground were obtained gradually by seed rain,among them 48.55% were eaten by insects,25.36% were carried by organisms or non-organisms,17.39% were decayed,8.7% were foraged by rodents and no seed germinated.All factors affected dynamics of the seed are variable seasonally.Soil provided with a safe enviroment for seed germination.Through observation of seeds which were buried by us,we found that the seeds in soil will last more than 250 days without obvious change and not germination until rain season next year.