Abstract: Objective To detect the level of annexin A1 (ANXA1) in the peripheral blood of patients with biliary tract tumors and analyze its clinical value in the early diagnosis of tumors and evaluation of disease progression. Methods The levels of serum ANXA1 before and after operation were detected by ELISA. Meanwhile, the levels of serum ANXA1 in health subjects were analyzed as controls. Results level of serum ANXA1 was (348.36 + 236.53) μg/L in patients with preoperative biliary system tumors, which were higher than that in healthy subjects (225.01 + 245.23) μg/L (P>0.05). After surgery, the level of serum ANXA1 was (148.14±39.83) μg/L, which were significantly lower than that before surgery (P<0.05). Conclusions The level of serum ANXA1 in patients with biliary tract tumors is higher than that in healthy subjects, and closely related to tumor residues or recurrence, which suggests that serum ANXA1 is a potential biomarker for judging tumor residues and predicting disease progression.