The present invention provides a method for forming a surface graft, comprising the process of applying energy to the surface of a substrate containing polyimide having a polymerization initiating moiety in the skeleton thereof, to generate active points on the surface of the substrate and to generate a graft polymer that is directly bonded to the surface of the substrate starting from the active points and that has a polar group, and a surface graft material obtained thereby. The present invention also provides a method for forming a conductive film, comprising the processes of applying energy to the surface of a substrate containing polyimide having a polymerization initiating moiety in the skeleton thereof, to generate active points on the surface of the substrate and to generate a graft polymer that is directly bonded to the surface of the substrate starting from the active points and that has a polar group, and causing a conductive material to adhere to the graft polymer, and a conductive material obtained thereby.