Porous anodic aluminum oxide（AAO） templates, obtained by anodization of aluminum sheets at relatively high voltages, were used for fabricating branched platinum nanowires which copy the three-dimensional branching structure of the nanochannels in the template. The formation of these branched nanochannels is the characteristic of AAO templates grown at 60 V in 0.15 mol/L H2C2O4 solution. When AAO templates are grown at 40 V or lower, straight channels and platinum nanowires are obtained. Platinum nanowires array was alter-current（AC）-electrodeposited in AAO at a lower frequency（20 Hz） and increasing voltage（5-15 V）. Compared with traditional AC electrodeposition condition, the deposition rate of platinum nanowires under this condition is slower and more controllable. Therefore, the platinum nanowires can perfectly copy the structure of the template. The as-obtained Al/AAO/Pt composite and branched platinum nanowires were characterized by X-ray diffraction（XRD） and transmission electron microscope（TEM）, respectively.
