Objective To detect the expression of ZMYND8 in gastric cancer tissuesand their adjacent tissues, clarify the relationship between the expression level of ZMYND8 and the clinicopathological parameters of gastric cancer patients, and analyze the relationship between the expression of ZMYND8 and the 5-year survival rate of gastric cancer patients. Methods The expression of ZMYND8 mRNA in 30 cases of gastric cancer fresh tissues and the adjacent tissues were detected by RT-qPCR. Immunohistochemical was used to detect the expression of ZMYND8 protein in 60 cases of tumor and paraffinic samples. The correlation between the ZMYND8 expression and the survival rate of patients was analyzed by K-M survival curve. Results The expression of ZMYND8 mRNA in gastric cancer was significantly lower than that in the adjacent tissues (P<0.01). The positive rate of ZYND8 protein expression in gastric cancer was 21.6%, which was significantly lower than that in the adjacent tissues (85.0%, P<0.05). ZMYND8 expression was closely related to the depth of tumor cell invasion, lymph node metastasis and TNM stage (P<0.05). The results of K-M survival analysis showed that the 5-year survival rate of patients with positive expression of ZMYND8 was significantly higher than that of patients with low expression (P<0.01). Conclusion The expression rate of ZMYND8 in gastric cancer is low and closely related to tumor invasion, lymph node metastasis, TNM stage and 5-year survival rate of patients, which suggest that detection of the expression of ZMYND8 is of great significance in predicting the prognosis of gastric cancer patients.