The highly ordered and vertically oriented pure TiO2 nanotube arrays (TONTAs) are synthesized by anodic oxidation of titanium foils in fluoride-based electrolytes under different temperatures and voltages.Then TONTAs are treated at different temperatures.X-ray diffraction (XRD) pattems show that its structure is anatase at 500 ℃ with the temperature increasing to 700 ℃,the most of anatase will transform to rutile,the nanotube arrays form granular titanium oxide,while at 900 ℃,anatase will transform to rutile completely.The experimental results of photocatalytic degradation of methylene blue solution show that the cobalt-manganese co-doped TONTAs have good photocatalytic degradation efficiency.