||ZnO films on glass tubes were prepared by chemical bath deposition method. The glass tubes were surface-activated by KMnO4(aq) and then submerged in an alkaline aqueous solution, containing Zn(CH3COO)2, NH4OH and HO(CH2)2NH2 at 75 oC to undergo film formation. The microstructures of the dried and calcined ZnO films prepared using different conditions were examined. The films formed on KMnO4-activated glass tubes are composed of steeple-typed wurtzite ZnO columns. Photocatalytic activities of the ZnO films were evaluated by photocatalytically degrading the methylene blue (MB) in water under UV-light irradiation. The apparent reaction order for MB photocatalytic degradation by the ZnO films was 1st-order and the reaction rate constants (k), based on the area of substrates coated by the film, were estimated. The ZnO films prepared using a volume ratio of ammonia/ethanolamine = 2/12 and calcined at 500 oC gave a photocatalytic performance with an average k = 0.5490.021 L/(m2·min).