Objective To explore the relationship between the abnormal expression of anti-oncogene PTEN in gastric carcinoma and the clinicopathological characteristics. Methods Mythylation specific PCR was applied to detect the expression of PTEN methylation in gastric carcinoma and their normal tissues from 45 patients. Results The methylation took place in 40.0 percent in gastric carcinoma and 2.2 percent in their normal tissues, and the difference was significant(P<0.05). The methylation rate in poorly differentiated adenocarcinoma was 60.0 percent ,while 15.0 percent in highly-moderately differentiated group, the difference was significant (P<0.05). In the 24 cases with lymph node metastasis, mythylation was observed in 13 cases, and the difference was significant (P<0.05). Conclusion The methylation of PTEN gene was associated with gastric carcinoma, it may play an important role in the development of the disease.