Abstract: Objective To analyze the effect of preoperative serum alanine aminotransferase(ALT) and asparagine aminotransferase(AST) ratio(LSR) on long-term prognosis in patients with gastric cancer undergoing radical gastrectomy. Methods Clinical data of 106 patients with gastric cancer in our hospital from January 2014 to December 2018 were analyzed. Patients were divided into two groups according to the level of LSR. The relationship between preoperative LSR and clinic pathological factors were analyze. The influence of preoperative LSR on long-term prognosis of gastric cancer patients was analyzed by Cox regression. Results The best cut-off point of LSR in ROC curve was 1.48, and 81 cases in LSR<1.48 group, 25 cases in LSR ≥ 1.48 group. Single factor results showed that the LSR was higher in patients with smoking, higher TNM staging and combined visceral resection(all P<0.05). A total of 98 patients(92.45%) were followed up for 22-86(median 43) months, and the 5-year survival rate was 39.80%. The 5-year survival rate of patients with LSR<1.48 was 44.44%, and patients with LSR ≥ 1.48 was 12.0%, with statistically significant difference(P<0.05). Multivariate Cox regression analysis showed that tumor size, TNM staging and LSR were independent factors affecting the prognosis of patients with gastric cancer(all P<0.05). Conclusion Preoperative LSR may be an independent factor to predict the prognosis of patients with gastric cancer. Therefore, the prognosis and survival time of patients with gastric cancer can be improved by restoring and improving their liver function.