Abstract: The photosynthetic characteristics,carbon ccumulation ,translocation and redistribution of summer maize were studied during the whole growing period under drought stress.The results indicate that the pattern of the carbon metaboli sm of maize is not significantly influenced by water deficient, although the total amount of accumulation, translocation, redistribution and transfer rates in the different growth stages are much different under drought. Under water stress,the dry matter and its accumulation rate of different organs are decreased. Leaf area index, leaf chlorophyll content and photosynthesis rate are reduced while the amount of dry weight transferred, transfer rate and the percentage of ear weight in the different organs are changed under drought.The treatment of full-water supply owns the largest dry matter accumulation and the normal carbon metabolism.The proper water supply can effectively promote the dry matter accumulation during the prophase growth stages, and it can also stimulate the vegetative organs to transfer to grain at the evening of growth stages. This suggests that the remained non-structive carbohydrates in vegetative organs are f ewer and the redistributed dry matter mainly contributes to higher grain weight, thus getting higher corn yields.