Disclosed is a method for preparing filled polypropylene compositions comprising mixing a dicarboxylic acid anhydride-grafted polypropylene resin and an ethylene/vinyl acetate copolymer or an ethylene/alkyl (meth)acrylate copolymer with polypropylene, filler and optionally an elastomer. Also disclosed are compositions comprising a dicarboxylic acid anhydride-grafted polypropylene resin and an ethylene/vinyl acetate copolymer or an ethylene/alkyl (meth)acrylate copolymer that can be used as compatibilizers or coupling agents allowing preparation of polypropylene compositions filled with, for example, glass fibers. The glass-filled resin composition exhibits excellent finishing properties, such as adhesion, coating properties, and printability, as well as improved rigidity and thermal properties.