Rhodamine B solution was photocatalytically degradated by ZnO film.The effects of pH of rhodamine B solution,initial concentration,H2O2,layers of the films,and illuminative time on the degradation rate were studied to determine the optimal parameters of degrading rhodamine B by ZnO films.The results indicated that the acid environment could enhance the photocatalytical activity of ZnO film;the low initial concentration of rhodamine B could accelerate the degradation speed;H2O2 could improve the degradation rate of rhodamine B;the degradation rate of three layer membrane was higher than that of single membrane for the rhodamine B.The degradation rate of rhodamine B reached 99.6% when the H2O2 was placed into 35 mL 5 mg/L rhodamine B with pH 1.46 and illuminated for 60 min by ultraviolet.