Abstract: Objective To investigate the expression of signal transducer and activators of transcription 3 (STAT3), p-STAT3 and the downstream transcriptional factor Bcl-xL and their effects in the tumorigenesis and development of gastric carcinoma (GC). Methods The expressions of STAT3, p-STAT3 and Bcl-xL in 53 cases of GC tissues and 44 cases of normal gastric mucosa tissues were assayed by immunohistochemical staining. The correlation of the expression of STAT3, p-STAT3 and Bcl-xL in GC with clinicopathological parameters was analyzed. Results The positive expressions of STAT3, p-STAT3 and Bcl-xL in GC were remarkably higher than those in normal gastric mucosa tissues (all P<0.01 ). STAT3 overexpression was correlated with tumor differentiation and lymph node metastasis (P<0.05), Expressions of p-STAT3 and Bcl-xL were correlated with tumor differentiation, depth of invasion, lymph node metastasis and clinical stage (all P<0.05), while they were not correlated with gender, age or tumor size (all P>0.05). Furthermore, expressions of p-STAT3 and BclxL showed linear positive correlation in GC tissues(r= 0.346,P=0.011). Conclusion STAT3 signaling pathway may play an important role in the tumorigenesis and progression of GC. Determination of STAT3 and its target gene Bcl-xL could be used to indicate the malignancy degree of GC.