Bismuth oxycholoride (BiOCl) nano/microstructures, including flake and nanowire arrays, were successfully synthesized on Anodic Aluminum Oxide (AAO) templates via sol-gel combined with the vacuum airextraction method. The flakes are almost vertically aligned on the surface, but nanowires at a lower sol concentration are aligned along the channels. A possible formation mechanism is proposed. Furthermore, the photocatalytic activity of the BiOCl nano/microstructures is investigated by photocatalytic decomposition of Rhodamine B (Rh B) dye under UV-Visible light irradiation. Compared with the BiOCl flake-like film on the glass substrate, where the flakes are horizontally oriented on the surface, the vertically aligned flake and nanowire arrays on AAO templates, have higher photocatalytic efficiency.