Complex symptoms often make it difficult to choose optimized strategies suitable for gastric patients.Therefore, molecular markers are needed to assist doctor’s diagnoses. In this study, to determine if themRNA levels of Th1 and Th2 cytokines in peripheral blood mononuclear cells (PBMC) of patients withgastric cancer were correlated with their various stages, gastric patients, patients with benign gastricdisease, and heathy people were recruited for detection of cytokine mRNA levels. Only the relative levelsin comparison with levels of each patient’s own β-actin were subjected to further statistical analyses. Wefound that there were significantly more positive detection of IL-4, IL-6, IL-10 mRNA expression in stageIII and IV than those in patients with gastic cancer in stage I and II. It was also found that IL-4, IL-6, IL-10mRNA expression in patients with low-level differentiations possessed significantly higher positive detectionratios than patients with moderate or high-level differentiation. These results suggest that positive detectionof IL-4, IL-6 and IL-10 mRNA may be useful as a molecular marker approach for distinguishing the stageII and III of gastric cancer, as well as low-level and moderate cancer differentiation.