Abstract: Objective:To investigate the proliferation of Lewis lung carcinoma（LLC） cells affected by the different concentrations of some drugs,including L-arginine、nitroglycerin and aminoguanidine,which regulate the nitric oxide level of cells.（Methods:）Cell morphlogy was performed and the MTT assay had been used to detect the proliferation of LLC cell and Griess assay to measure the cellular metabolites of nitric oxide derivatives.Results:All three drugs reduced inhibition of LLC cell proliferation with concertration falling continually,at the same time NO_2- level also increased in L-arginine and aminoguanidine treatment groups,but there was a positive correlation between NO_2- level and nitroglycerin concertration in nitroglycerin treatment groups.In tests of regulation of drug combination,there was an antagonistic joint action between L-arginine and aminoguanidine treatment in certain concertrations,and had a synergistic joint action between nitroglycerin and aminoguanidine treatment mostly.（Conclusion:Nitric） oxide maintains the bi-direct effect on tumor cell proliforation and Nitric oxide level produced by LLC cells was related to proliforation activity.