Pot experiments were conducted to study the effect of short-term drought at four rice growth stages on leaf water potential, photosynthesis and dry matter partitioning in paddy rice. The leaf water potential of rice plant under water stress was lower than that of CK, and the difference increased after midday. The predawn leaf water potential of rice plant decreased significantly when soil water content or soil water potential went down a threshold value, resulted in an obvious decline in the single leaf net photosynthetic rate. In compared with the well-watered treatment, the net photosynthetic rate under severe water stress decreased by more than 50%. The partitioning indexes of leaf, root and spike decreased, while that of stem and sheath increased after short-term drought.