Abstract: To evaluate the relationship between the expression of CD and bi0l0gical behaviour ofBTCC, 33 paraffin - embedded tissue specimens of BTCC were examined by the standard ABC immunohistochemical technique. The result revealed that all normal transitional cells were weakly stained and the5trongly positive rate of CD in BTCC was significantly higher than in normal control group (P 0. 05).Pisher's accurate analysis showed that strongly positive expression of CD in tumour cells closely corrlatedwith different patholbgical grades (P 0, 05), clinical stages (P 0. 05), number of lesions (P 0. 05), and postoperative reccurance (P 0. 05). It was suggested that expression of CD closely cor-elated with grades and stages and it played the important role in the process of invasiveness and metastasisof BTCC by lowering the function of nature defences.