ObjectiveTo investigate the expression of proapoptosis gene bad in intrahepatic cholangiocarcinoma (ICC) and its relationship to differentiation of the tumor.MethodsThe immunohistochemistry technique by Dako Envision system and rabbit antihuman bad polyclonal antibodies were adopted. The expression of bad was detected in 48 cases of ICC and 25 cases of control tissues.ResultsBad immunoreactivity in 48 cases of ICC was higher than that of bile duct epithelium in 25 cases of control tissues. And contrasted with 21 cases of well differentiated ICC, bad immunoreactivity was higher in 27 cases of middle and poor differentiated ICC.ConclusionThe expression of bad gene may be related to the differentiation of ICC.