To evaluate the relations between the protein nm23 expression and infiltration and metastasis of gastric cancer. Sixty seven samples of gastric cancer resected were examined with LSAB-immunohistochemical method, and the protein nm23 expression in gastric cancer cells were studied. Results: Total positive rate of the protein nm23 expression in gastric cancer cells was 68.7%. There were significant differences among different histopathological types degrees of differentiation, extent of infiltrative and metastasis (Ｐ＜0.05). Conclusion: The positive rate of protein nm23 expression in gastric cancer cells is 68.7%, which is highly related to the pathological type degree of differentiation, extent of infiltration and metastasis of the tumor.