Objective: To investigate the expression of JAK2/STAT3 signaling pathway in human hepatocellular carcinoma (HCC) tissue and its significance. Methods: The protein expressions of JAK2 and STAT3 in specimens of HCC tissues and matched adjacent non-cancer tissues from 75 patients were detected by immunohistochemical staining and Western blot analysis. The relations of their expressions with the clinicopathologic features and prognosis of the patients were analyzed. Results: Both positive expression rate (62.7% vs. 5.3%; 69.3% vs. 9.3%) and expression level of either JAK2 or STAT3 protein in HCC tissue were significantly higher than those in the adjacent non-cancer tissue (all P<0.05); there was significant correlation between the expressions of JAK2 and STAT3 protein in HCC tissue (r=0.383, P<0.01). Both expressions of JAK2 and STAT3 were significantly related to cirrhosis, portal vein tumor thrombus, degree of tumor differentiation, and clinical stage (all P<0.05). Survival analysis showed that both survival rate and survival time in patients with high JAK2 or STAT3 expression were significantly decreased compared with corresponding low expression cases (χ2=13.591; χ2=6.842, both P<0.05). Cox proportional hazard regression model analysis indicated that the expression of JAK2 and STAT3 protein along with portal vein tumor thrombus, degree of tumor differentiation, clinical stage were independent risk factors for HCC (all P<0.05). Conclusion: The activity of the JAK2/STAT3 signaling pathway is increased in HCC tissue and the degree of its activation is closely related to the prognosis of HCC patients.