A brief summary on the concept of seed ecology is presented, and then its four hot research topics are introduced in detail. They are seed rain and seed dispersal ecology, seed mass ecology, soil seed bank ecology, and seed geography. On the basis of previous published theories, their research methods, research content, scientific questions, conclusions, and future research directions are addressed and summarized. Seed ecology is a developing science which studies the relationships between seed and its environment, it has lots of research contents, in which the relationships between seed germination and environment have been received more attention; however other aspects of seed ecology research are comparatively scant. Future research in seed rain are as follows: (1) to investigate seed rain characteristics of community or population types; (2) to observe seed rain for a long term; (3) to trace final destiny of dispersed seeds, and (4) to explore the geographical dispersal patterns of seed rain characteristics, such as densities of seed rain and species richness of seed rain. Future research directions related to seed mass are: (1) to explore co-evolutionary between seed mass and more micro-biological traits, such as cell biology, plant anatomy, biological chemistry; (2) to collect seeds in more regions and to found more relationships between biological macro-characteristics and seed characteristics combined with sampling materials based on more species. As for soil seed banks, future research works are: (1) to investigate species composition and seed densities of soil seed bank and its inter-annual dynamics; (2) to explore geographical variation patterns of soil seed bank traits. In seed geography, the following research regions should be paid attention to: (1) the geography of seed morphology and anatomy characteristics; (2) the geography of seed biochemical components; (3) the geography of seed physiological traits; (4) the geography of seed cell biology; (5) the geography of seed genetic traits, and (6) the geography of flowers and fruits.
