Abstract: The research achievements in the developmental biology and the genetic ecology of hybrid rice in the past decade were summarized, including accumulation and transportation of dry matter, changes in anatomic structure of caryopsis, related enzyme activity, endogenous hormone contents, and starch accumulation in strong and weak grains at the filling stage as well as the dynamic genetic property of caryopsis development, cytoplasmic effect on the grain filling process in hybrid rice exposed to different ecological conditions.The main issues in the present research on grain yield and quality formation of hybrid rice were explicated and discussed.New idea and its approach were outlined for the development of modern crop cultivation science.