Abstract: Dry matter accumulation pattern of high yielding hybrid rice colony appeared as Logistic curve with the highest accumulation speed at meiosis stage.The accumulation amount was the maximurn in middle period(panicle initiative differentiation to heading),the second in later period(after heading)and the little in earlier period(before oanicle initiative differentiation).There were relevantlv different dry matter distribution centers in various growth stageS of rice.The distribution center in earlier period was leaves and sheaths,in middle period was leaves,sheaths and stems,and in later period was panicles, About 73%～75% of panicle filling matter was from photosynthesis after heading,and 27%～25% from the transportable storage matter in vegetatibve organs.Among the total transporting matter of vegetative organs,about 80% was storage carbohydrates and 6% was N P K The advantageous light and temperature condition in middle and later periods of earller crop promoted the dry matter production of hybrid rice,which made the grain yield of earlier crop rice much higher than that of later crop rice.