Abstract: Objective To evaluate the value of anti-ferritin light chain(FTL) autoantibody in the diagnosis of common malignant gastrointestinal tumors.Methods The serum levels of anti-FTL autoantibody in different groups,including a variety of gastrointestinal tumors(250 esophageal cancer patients,250 gastric cancer patients,250 primary hepatocellular carcinoma(HCC) patients,chronic liver diseases patients(120 hepatitis B patients,54 hepatitis C patients,58 liver cirrhosis patients),and 113 normal individuals,were measured with enzyme-linked immunosorbent assay(ELISA),then the content and the positive rate of anti-FTL autoantibody in different groups were analyzed and compared.Results 1.The anti-FTL autoantibody levels in gastrointestinal tumor groups were all significantly higher than normal individuals(all P<0.001).Compared with esophageal cancer patients or gastric cancer patients,the anti-FTL autoantibody levels in primary hepatocellular carcinoma patients were significantly higher(all P<0.001).2.The anti-FTL autoantibody levels in primary hepatocellular carcinoma patients were higher than those with chronic liver diseases(P=0.001).Further more,the anti-FTL autoantibody levels in those with chronic liver diseases were significantly higher than that of normal individuals(P=0.000).3.The positive rate of anti-FTL autoantibody in cancer groups was significantly higher than that of normal subjects(all P values were less than 0.001).4.The sensitivity of anti-FTL autoantibody in the detection of gastrointestinal tumors(esophageal cancer,gastric cancer and HCC)was 46.8%,48.4%,and 61.6%,respectively,and the specificity was 99.1%.Conclusion The concentration of anti-FTL autoantibody increases in gastrointestinal tumor patients and the increase is significant for the the diagnosis of common malignant gastrointestinal tumors.