We demonstrated a practical process of fabricating nickel molds for nanoimprinting. Dual-side polished glass is chosen as the substrate on which nickel nanostructures are successfully electroplated. Photonic crystal structures with 242 nm diameters and other nanoscale pillars down to 9 nm diameters are achieved over a large area. The electroplating parameters are investigated and optimized. This process extends the feasibility of electroplating process to nanoscale and shows great potential in nanoimprint mold fabrication with its low cost, straightforward process and controllable pattern structures.