Objective To investigate the inhibitory effect and the mechanism of endostatin on human gastric carcinoma model in nude mice. Methods Athymic mice were injected by in vitro-cultured SGC-7901 human carcinoma cell strain to observe the inhibitory effect of endostatin. Real time fluorescent quantitative PCR and immunohistochemistry stain were used to quantify the expression levels of Bcl-2 and Bax genes both on mRNA and protein levels. Results The average tumor volume in endostatin group was statistically smaller than control group (P<0.05). The inhibitory rate on the 7~(th), 10~(th), 13~(th), 16~(th) and 19th day was 26.2%, 47.7%, 38.9%, 45.8% and 51.7%, respectively. The results of real time fluorescent quantitative PCR demonstrated that mRNA expression of Bcl-2 in endostatin group was obviously lower than it in control group (P<0.05), however, the expression level of Bax had no statistical difference between these two groups (P>0.05). The results of immonohistochemistry were consistent with PCR. Conclusions Endostatin can inhibit the proliferation of SGC-7901 human gastric carcinoma in athymic mouse model, and the mechanism involves the suppression of Bcl-2 expression.