Difference at microhabitats in forest ecosystems may affect seed germination and seedling establishment, lead to various species distribution patterns. In order to explore effects of habitat heterogeneity on plant distribution pattern, we dispersed seeds of Baccaurea ramiflora and Saprosma ternata at five microhabitats which have difference in elevation and topography, in a Xishuangbanna tropical seasonal rainforest. The dynamics of seed germination and seedling survival were monitored. The corresponding land surface (3 cm above the ground) temperature, air humidity (3 cm above the ground) and topsoil (5 cm deep) water content at microhabitat were also recorded. Meanwhile, seed desiccation under ambient regime and germination under water stress were performed. It was found: (1) at five microhabitats, soil water content at valley bottom kept the highest all the year round; Air relative humidity was saturated on rainy season and fogy season. Only on dry season there is obvious difference, namely with the increase of altitude, the air humidity dropped; Mountain temperature inversion which last one or two months occured on dry season. (2) In addition, B. ramiflora and S. ternata seeds had different dispersal and germination pattern. S. ternata seed had significant difference in seed germination and seedling survival at different habitats. B. ramiflora had seed dispersed and quickly germinated on rainy season, and its seed had the ability to germinate under relatively lower water potential, so it spent dry season by seedling; While S. ternata dispersed seed in the end of rainy season, which was dormant and relatively desiccation resistant, it pass spent through dry season by seed. In conclusion, topographical condition is a critical factor to effect microhabitats heterogeneity in Xishuangbanna tropical seasonal rainforest, and the difference in temperature and water regime among these five microhabitats is most obvious on dry season, which had important effect on seed germination and seedling survival of B. ramiflora and S. ternata.On the other hand, B. ramiflora and S. ternata seeds have different strategy to cope with drought in Xishuangbanna tropical seasonal rainforest because of their seed traits.