Abstract: Objective To detect the level of ANXA1 in peripheral blood of patients with biliary tract tumors and to analyze its clinical value in the early diagnosis of tumors and evaluation of disease progression. Methods The expression of ANXA1 in serum before and after operation was detected by enzyme-linked immunosorbent assay. Results The serum ANXA1 level was 348.36 + 236.53 ug/L in patients with preoperative biliary system tumors, higher than that in healthy controls (225.01 + 245.23 ug/L (P=0.1717). The serum ANXA1 level was 148.14 + 39.83ug/L, significantly lower than the preoperative serum ANXA1 level, P=0.0326. Conclusion Serum ANXA1 level of patients with biliary tract tumors is significantly higher than that of healthy people, and is closely related to tumor residual or recurrence in patients, suggesting that serum ANXA1 detection is a potential biomarker for judging tumor residual and predicting disease progression.