Abstract: Objective　To determine the prevalence and potential clinical value of mdm2 amplification in cardia gastric carcinoma.Methods　Mdm2 amplification was examined by differential polymerase chain reaction (dPCR).Results　Mdm2 amplification was found in 7 of 38 cases (18.2%). Otherwise, the positive rate of mdm2 gene amplification in higher grade group was higher than that in the lower grade group (33.3% vs 5%), and the difference was significant (P<0.05). There was no correlation observed between the alteration and other clinicopathological parameters, such as sex, age, histological subtype, lymph node metastasis,et al. Conclusion　The data suggest that mdm2 amplification might play an important role in cardia gastric carcinoma. It maybe a mechanism for cells to escape from the regulatory pathway of p53. The detection of the alteration may be helpful to assess the prognosis of cardia gastric carcinoma.