To seek ways for improving salt\|tolerance of wheat plants, experiments were conducted to examine the ameliorative effects of Ca2+ on nitrogen metabolism under salt stress using an ordinary wheat cultivar (Triticum aestivum L. cv. Yumai 34) as the material. The wheat seedlings were cultured in full nutrient solution. The first leaf being fully expanded, different treatments were initiated by culturing the plants in the nutrient solution without calcium. NaCl (150 mmol?L-1 and 300 mmol?L-1) and combinations of NaCl + Ca2+ (150 mmol?L-1 + 4 mmol?L-1 and 300 mmol?L-1 + 4 mmol?L-1) were applied to the growing plants using no salt\|stressed plants as control. After 5 days of treatments, the activities of nitrogen assimilation enzymes, the amount of nitrogen assimilation and the growth status of wheat seedlings were determined. The results showed that Ca2+ significantly alleviated the depressed\|growth of wheat seedlings under low salt stress, manifesting the enhanced fresh weight, chlorophyll and soluble protein contents; while Ca2+ did not show obvious ameliorative effects under high salt stress. Ca2+ promoted the nitrogen assimilation and improved the status of nitrogen nutrition in wheat plants exposed to low salt stress, which could be mainly due to the enhanced activities of nitrate reductase (NR), glutamine synthetase (GS) and NADP\|dependent isocitrate dehydrogenase (NADP\|ICDH). The minor ameliorative effects of Ca2+ on nitrogen assimilation in wheat seedlings under high salt stress could be explained by the insignificant increase of NADP\|ICDH activity.