Abstract: Fibronectin in 49 cases of transitional cell carcinoma(TCC) of bladder was investigated by ABC immunohistochemical method.The results revealed that:there are three types of FN expression,pericellular,stromal,and cytoplasm.FN in pericellular and stromal of TCC was decreased in pace with escalation of histological grade but it was increased in cytoplasm.The results indicated that:these alternations may be a important foundation of metastasis and infiltration in TCC,and it may correlated with prognosis of TCC.