In order to solve the problem caused by the late maturing tobacco,the effects of different concentrations of Na2WO4 sprayed in overgrown tobacco plants on the tobacco root activity,nitrogen metabolism,antioxidant system,nicotine content were studied using K326 as the research object.The results indicated that the root activity,nitrate reductase(NR)activity,glutamine synthetase(GS),malondialdehyde（MDA）content were negatively correlated with the concentration of Na2WO4.The activities of invertase(Inv),SOD,and POD were increased,which were positively correlated with the concentration of Na2WO4.At the same time,the content of nicotine was decreased.In general,spraying 1.0 mmol/L of Na2WO4could effectively inhibit the nitrogen metabolism of tobacco leaves,and promote tobacco leaf turning yellow,improve the ability of tobacco resistance to oxidative stress,and reduce the nicotine content of tobacco leaves.