It is impossible to judge the value of CA199 decrease after bile duct cancer surgery; CA199 may decrease or increase after bile duct cancer surgery. CA199 is a tumor marker, the decrease of its value after surgery indicates that the surgery is more effective, and if it is elevated, it indicates that cholangiocarcinoma has the possibility of recurrence and metastasis; most of the patients’ condition will be stable after surgery, the value of CA199 will gradually decrease, but the value can not be quantified, and if the cholangiocarcinoma recurs after surgery, the CA199 will be elevated. Cholangiocarcinoma requires reasonable choice of adjuvant treatment according to the pathological type of patients in order to achieve the purpose of controlling the development of the disease so as to improve the quality of patient’s survival; according to the different conditions of the disease, the value of CA199 may not necessarily be completely reduced to below normal value. After the surgery, regular review should be conducted, and the corresponding treatment plan should be adjusted in time according to the situation to avoid the development of the disease.