Objective To investigate the expression of Oct4 protein and analyze its correlation with the clinic pathological features and prognosis of non-muscle-invasive bladder cancer.Methods The oct4 protein expression was assessed by immunohistochemical analysis in 87 specimens of bladder transitional cell carcinoma and 15 specimens of adjacent normal tissues.A correlation between Oct4 and clinic pathological features was analyzed.Results The positive rate of Oct4 protein was significantly higher in bladder cancer than that in normal bladder tissue (P＜0.01).The positive rate of Oct4 protein was 40.7％ in G1 bladder cancer,69.4％ in G2 bladder cancer and 91.7％ in G3 bladder cancer,and the differences was significant (P＜0.01).All patients were followed up for 3-78 months,and 63 of them relapsed.The expression of Oct4 protein was significantly higher in patients of recurrence than in non-recurrence (77.8％ ∶ 37.5％,P ＜ 0.01 ).21 patients of recurrence were in progression,and the expression of Oct4 protein had no significant differences between patients of progression and non-progression (71.4％ ∶65.2％,P ＞0.05).The positive rate of Oct4 protein was not related with gender,age,tumor number and size (P ＞0.05).Conclusion The detection of Oct4 protein is in favor of early detection of bladder tunor,estimation the degree of differentiation and surveillance for recurrence of superficial bladder cancer.