【Abstract】 Objective To investigate the relationship between the expression of nucleophosmin (NPM) in gastric cancer tissue and clinicopathologic factors and prognosis, and evaluate the role of NPM in gastric cancer invasion and metastasis and the significance of predicting prognosis in gastric cancer patients. Methods We examined the NPM expression of 82 gastric cancer and 36 gastrectomy mucosal tissue away from the cancer tissue more than 5cm by immunohistochemical method and evaluated the correlation between NPM expression and clinicopathological factors (age, sex, histology, tumor depth, lymph node status, clinical stages and recurrence). We assessed the postoperative survival rates of gastric cancer by KaplanMeier method, univariate Cox regression analysis, and multivariate Cox regression analysis. Results NPM expression was detectable in 54 of the 82 tumors (659%) and in 7 of 36 gastrectomy mucosal tissue away from the cancer tissue more than 5cm (194%). There was significant differences on their positive expression rates between in gastric cancer tissue and in normal gastric mucosa(P＜0001). NPM positivity was significantly correlated with the Lauren’s classification (P=0025), nodal involvement(P=0001), depth of invasion (P=0010), clinical stages(P=0033) and recurrence (P=0006). There were no significant differences between the positive expression rates of NPM and age, gender, tumor size and differentiated degree. Survival analysis of gastric cancer patients showed that the survival rate of NPMnegative group and NPMpositive group was significant differences (P=0021). Conclusion These results suggest that NPM positive expression is strongly related to the invasion and metastasis of gastric cancer, and NPM can be used as a prognostic biomarker of gastric cancer.