To detect the expression of E-Cadherin and α-Catenin in bladder transitional cell carcino ma (BTCC) and analyze its correlation with the biological behavior of BTCC. Methods:The immunohistochemical staining with strept avidin-biotin-peroxidase complex method (SABC method) was used to detect the expression? of E-Cadherin and α-Catenin in 65 paraffin embeded BTCC tissues. Results :The normal expression rate of E-Cad herin was 76.2％ of G1 ,34.8％ of G2,4.8％ of G3,54.1％ of Tis～T1 and 17.9％ of T2～T4 tumors respectively. The normal expression rate of α-Catenin was 71.4％ of G1,34.8％ of G2,4.8％ of G3, 51.4％ of Tis～T1 and 17.9％ of T2～T4 tumors respectively. The expression of either E-Cadherin or α-Catenin was significantly corre lated with pathological grade,clinical stage of BTCC ( P＜0.01). E-Cadherin and α-Catenin expression was con comitantly either normal or abnormal in 83.1％ of tumors. The correlation between E-Cadherin and α-Catenin ex pression was significant ( P＜0.01). There was a significant difference in recurrence rate between normal E-Cad herin expression team and abnormal E-Cadherin expression team and between normal α-Catenin expression team and abnormal α-Catenin expression team ( P＜0.05). Conclusions: Detection of E-Cadherin and α-Catenin ex pression have a practical significance in assessing the malignancy and recurrence of BTCC.