Objective To observe the expression of adenovirus vector coding for mouse endostatin gene（Ad-mES） in lung cancer cells and its antiangiogenic activity in human umbilical vein endothelial cells（ECV304） in vitro.Methods Lewis lung cancer（LLC） cells were transfected with Ad-mES at different multiplicity of infection（MOI）.The expression of mES in LLC cells and supernatant after 48 hours was detected by immunohistochemical staining and Western blot respectively.The inhibitory effect of supernatant at different MOI on ECV304 non-stamulated and stimulated by basic fibroblast growth factor（bFGF） was measured by methyl thiazolyl tetrazolium（MTT） assay.Results After transfected for 48 hours，endostatin was identified in the cell plasma of infected LLC and negative result was founded in non-infected LLC.Western blot revealed band of endostatin in 20 kDa in culture supernatant of infected LLC and negative results in non-infected LLC.The inhibitory effects on ECV304 cell proliferation were ber at higher MOI，and the difference was significant between stimulated and non-stamulated cells by bFGF（Plt;0.05）.Conclusion Ad-mES can transfect and express endostatin effectively in LLC with biological activity