Zinc-doped TiO2 nanotube arrays were fabricated by immersing TiO2 nanotube arrays in zinc-containing solution for hours. And subsequent heat-treatment was crucial for Zn2+ coming into the crystal lattice of TiO2 nanotubes. TEM analysis was used as main technique to investigate the structure of zinc-doped TiO2 nanotubes, and found that the Zn2+ ions only combine into the lattice of TiO2 nanotubes. This kind of doping can change the valence structure in the surface of TiO2 nanotube array. The obtained zinc-doped TiO2 nanotube arrays have potential application in photocatalysis.