Titanium dioxide(TiO2)nanotube arrays were prepared by anodic oxidation,CdSe/TiO2 nanotube arrays composite films with three-dimensional heterogeneous structures were prepared by different electrochemical methods.The results show when sodium potassium tartartrate was added into the electrolyte,CdSe nanoparticles with good dispersion,small size and uniform distribution are obtained both by cyclic voltammetry and potentiostatic deposition.Especially,the cubic phase CdSe particles with a diameter of 15 to 20 nm are obtained by using cyclic voltammetry,which are distributed uniformly on the inner and pipe mouth of TiO2 nanotubes,so as to make full use of the three-dimensional structure of TiO2 nanotube arrays,and obtain CdSe/TiO2 nanotube arrays composite films with three-dimnsional heterogeneous structures.Through photoelectric chemical testing,the results show that CdSe/TiO2 nanotube arrays composite films with three-dimensional heterogeneous structures can make full use of solar energy,effectively promote the separation and transmission of photon-generated carriers,and present the best photochemical properties.