Objective To study the significance of alteration of concentration of endothelins(ET) and calcitonin gene related protein(CGRP) in bile in patients with acute choiangitis of severe type(ACST). Methods The concentration of ET and CGRP were detected by radioimmunoassay in 55 cases of ACST at openation time, and 7th, 14th day after operation. Results Compared with the control group, the concentration of ET in bile in patients with ACST was significantly higher at operation time(P<0.01~0.001). The concentration of ET in bile also showed significant difference at operation time between the 2 groups with different ACST severity(P<0.05). The concentration of ET in bile gradually reduced after operations. Compared with the control group, the concentration of CGRP in bile was signficantly lower at operation time(P<0.01). CGRP in bile gradually rose after operation. Conclusions The ET in bile has some effect on the ACST pathologic alterations. The content of ET in bile is related to the severity of ACST. The disturbance of the balance between bile ET and CGRP may contribute to the pathologic process of liver and bile duct injury in ACST.