To analyze the expression of serum exosome membrane type 1-matrix metalloproteinase (MT1-MMP) mRNA in patients with gastric cancer and its relationship with prognosis.Methods 98 patients who underwent gastric cancer resection in the hospital from March 2016 to July 2018 were selected as the research subjects.RT-PCR was used to determine the expressions of MT1-MMP mRNA in cancer tissues and adjacent normal tissues of patients. The relationship between clinicopathological parameters and expression level of MT1-MMP mRNA in gastric cancer tissues was analyzed.Follow-up was performed on 98 patients, and the survival rate within 3 years after surgery was statistically analyzed.The expression levels of MT1-MMP mRNA in gastric cancer tissues and adjacent tissues of patients in survival subgroup and death subgroup were compared, and receiver operating characteristic curve (ROC) was used to analyze the predictive efficiency of MT1-MMP mRNA expression level on survival status within 3 years after surgery. Results The expression level of MT1-MMP mRNA with (0.96±0.12) in gastric cancer tissues of 98 patients was obviously higher than (0.80±0.09) in adjacent tissues (P＜0.05).The expression level of MT1-MMP mRNA in gastric cancer tissues of patients was related to the lymph node metastasis, degree of infiltration, and TNM staging (P＜0.05), but was not related to gender, age, tumor location, tumor diameter and differentiation degree (P＞0.05).Among the 98 patients, the expression levels of MT1-MMP mRNA in gastric cancer tissues and adjacent tissues of survival subgroup (n=62) at 3 years after surgery were markedly higher compared with those in death subgroup (n=36) (P＜0.05).ROC curve analysis showed that the expression level of MT1-MMP mRNA in adjacent tissues had obvious limitations in predicting the survival status at 3 years after surgery (AUC=0.691), and the combined detection of gastric cancer tissues and adjacent tissues had good predictive efficiency (AUC=0.813).Conclusion The expression of MT1-MMP mRNA in gastric cancer tissues is related to the lymph node metastasis, TNM staging and degree of infiltration, and can guide the prognosis to some extent