【Abstract】 Objective To investigate the correlation of PIAS3 expression level with clinicopathological features and prognosisin gastric cancer (GC) patients. Methods The cancer tissues (study group) and adjacent normal tissues (control group) of 112 patients with GC diagnosed in our hospital from January 2006 to May 2008 were selected. Then the expression levels of PIAS3 in both groups were detected by immunohistochemical staining, and its correlation with clinicopathological features and prognosis was also analyzed. Results The high expression rate of PIAS3 in the study group was lower than that of the control group (P＜005). The expression level of PIAS3 was not correlated with gender, age, tumor size, tumor location and Lauren classification (P＞005), while was correlated with tumor invasion degrees and lymph node metastasis (P＜005). The survival curves of GC patients with different PIAS3 expression was significantly different (P＜005). The mortality risk was significantly higher in patients with low PIAS3 expression than in patients with high PIAS3expression (P＜005).Conclusion The expression level of PIAS3 protein in GC tissues is relatively low, which is correlated with tumor invasion, lymph node metastasis and prognosis.