Objective To analyze the expression of suppressor of cytokine signaling 1 (SOCS1) in gastric cancer tissues and its relationship with the clinicopathological parameters, and to explore the clinical significance of SOCS1 as the prognostic indicator of gastric cancer patients. Methods Sixty-seven pairs of gastric cancer tissue and adjacent tissue specimens were collected to establish tissue microarray from the gastric cancer patients without preoperative radiotherapy or chemotherapy history, and the expression level of SOCS1 was detected by immunohistochemical SP method. χ² test was used to analyze the relationship between SOCS1 protein expression and clinicopathological parameters of the patients. Kaplan-Meier survival curve and log-rank test were used to analyze the relationship between SOCS1 protein expression and survival of patients. Cox proportional hazards regression model was used to analyze the relationship between SOCS1 protein expression and prognosis. Results The positive expression rate of SOCS1 was 80.6% (54/67) in gastric cancer tissues and 61.2% (41/67) in adjacent tissues, and the difference was significant (P<0.05). Incidence of lymph node metastasis in the patients with positive expression of SOCS1 was significantly higher than that in the patients with negative expression of SOCS1 (74.1%[40/54] vs 38.5[5/13], P<0.05). Kaplan-Meier survival analysis showed that the total survival rate of the patients with positive expression of SOCS1 was significantly lower than that of the patients with negative expression of SOCS1 (P<0.05). Cox proportional hazards regression model showed that SOCS1 and TNM stage were independent prognostic factors in patients with gastric cancer. Conclusion SOCS1 is highly expressed in gastric cancer, and it may be used as an important indicator for predicting lymph node metastasis and evaluating prognosis of gastric cancer patients.