Abstract:In light of the field-investigation at the fixed position from 1982—1988, a quantitutive analysis was done on the change of seed rain, and the relationships between the seed rain and water-heat climatic factors in Spipa grandis community was discussed in this paper. There were 46 plant species altogether and 9 of which were constant species in the seed rain of the community. The density of S. grandis which is dominant species was only about 0.3—1.3% in the total density of the seed rain every year. The seed rain density of dicotyledon group was generally about 1.5—13.5 times higher than that of the monocotyledon group, and the perennial group were 0.2—7.4 times higher before 1985,but 0.4—1.0 times lower after 1986 than the annual group in the community. The ratios of hemicryptophytes were usually the highest in life form spectrum of the seedrain plants every year. There was positive correlation of different value between the seedrain densities of both some plant groups and constant populations and the sunshine hours,the accumulated temperature, the rainfall in the earlier-middle growing season, and the rainfall in different periods preceding growing season respectively.