A modified Hoagland solution culture experiment was conducted to study the effects of Mo on nitrogen metabolism and the difference of Mo-efficient and Mo -inefficient winter wheat cultivars.The results showed that application of Mo significantly increased the activities of nitrate reductase and glutamine synthetase,decreased the content of nitrate.The contents of ammonium,total free amino acids and soluble protein were improved,indicating that the nitrogen metabolism of winter wheat was promoted by applying Mo.Genotypic differences in response of molybdenum on nitrogen metabolism were found between Mo-efficient and Mo-inefficient winter wheat cultivars.The changing rates of nitrate reductase and glutamine synthetase,the contents of nitrate,free amino acids and soluble protein in shoot and free amino acids in root of Mo-inefficient cv.97014 under Mo application were higher than those of Mo-efficient cv.97003.