Abstract: Objective To explore the joint determination of the serum pepsinogen PGⅠ,PGⅠ/PGⅡ and carbohydrate antigen 199(CA199),carbohydrate antigen 242 (CA242),carcino-embryonic antigen (CEA) on the clinical significance of early diagnosis of gastric cancer. Methods In the serum pepsinogen PG(PGⅠ,PGⅠ/PGⅡ) latex-enhancedimmunoturbidimetic,the tumor markers CA199,CA242,CEA with chemiluminescent particles immune method,130 cases of gastric cancer patients was detected for gastric cancer patients are pathological diagnosis clear,30 patients with gastric benign disease,120 cases of normal healthy check-up crowd,statistical analysis of the differences between three groups.Compare the sensitivity and specificity of single and joint index to see whether there is significant difference. Results The serum levels of five tumor markers(CEA,CA199,CA242,PGⅠ and PGⅠ/PGⅡ) in gastric malignant tumor were significantly different from those in benign gastric disease and control group(P<0.01).The sensitivity of the joint detections of the five tumor markers(86.1%) were significantly higher than that of the respective detection(P<0.01).However,there was no difference in specificity(P>0.05). Conclusion The positive rate of the joint detection of serum PGⅠ and PGⅠ/PGⅡ,CA199,CA242,CEA in gastric cancer patients is far higher than that of any single biomarker detection.Joint detection to improve detection rate early gastric cancer patients has clinical practical value.