Abstract:To accumulate the information for research on diffusion mechanism and ecological effect of Oenothera laciniata Hill, the community invaded by O. laciniata in Wenzhou, Zhengjiang Province and the seasonal dynamics of specie composition in soil seed bank were studied based on field investigation and germination experiment. The results showed that there were 46 species in the soil seed bank, and the species richness and their abundance among the soil layer showed remarkable difference, in the order as 0~2 cm>2~5 cm>5~10 cm. The Sorensen’s similarity coefficient for species composition aboveground and in the seed bank was 0.632, showing that the invaded community was at the initial stages of succession. The seed of O. laciniata had a characteristic of dormancy, and seed could periodically break dormancy at the process of bud. The importance value of O. laciniata in the community had positive correlation with the species diversity of community, but not significantly (P>0.05). It is proper time to control the spread of O. laciniata by eradicating it at its vegetative growth phase from November to next April .