Polysilanes possess both electrical and optical functionalities. To use a polysilane in electronic devices, it must be chemically modified to connect to a metal atom. We developed a synthesis method for a polysilane-methacrylate copolymer using a polysilane as the photoradical initiator because methacrylate can be easily modified. Notably, both ends of the polysilane block are expected to be modified with methacrylate, which has a reactive functional group, to form chemical bonds with the metal electrodes in electronic devices. In this study, we prepared a polysilane-methacrylate copolymer with two methacrylate species. The methacrylates used for photopolymerization were 2-(methylthio)ethyl methacrylate and glycidyl methacrylate.