Abstract: In this paper, the spring wheat (cv. Xihan No. 2) was taken as research material to investigate the dynamic changes of the nonstructural carbohydrates （NSC） in flag leaves, stems and leaf sheaths and activities of carbonmetabolizing enzymes (SSS, GBSS) in grains during wheat development process under various water stresses by water stress and rewatering treatment methods. The results indicated that various water stresses had no significant effects on the sucrose contents in flag leaves, stems, leaf sheaths and other organs of wheat. With the increase of water stress, the content of starch in flag leaves was significantly increased within 12-18 d after flowering. Water stress shortened the starch accumulation period in stems and sheaths after flowering and inhibited the transformation and distribution of starch in wheat stems. The accumulation of starch in sheath also gradually increased, which was early terminated under moderate water stress. At the beginning of the water stress, the contents of NSC in vegetative organs were listed as: flag leaves > stems > leaf sheaths. With the increase of water stresses, the NSC contents in vegetative organs were listed as: stems > flag leaves > leaf sheaths. We could conclude that the changes in main NSC (sugar, starch) distribution and carbon-metabolism enzyme activities was a kind of physiological regulation response of wheat to water stresses.