''Active'' poly(methyl methacrylate) having peroxygen groups of 1.6 wt-% and with M(n)=15000 g/mol, were prepared and used in the free radical coupling reactions of polybutadiene. Poly(methyl methacrylate)-polybutadiene cross-linked and soluble graft copolymers were obtained in moderate yields. Swelling degrees of the cross-linked block copolymers in CHCl3 were between 319-759. NMR and FTIR spectra were containing the characteristic bands of the graft copolymers. Broad melting peaks on DSC curves of the graft copolymers appear from about 40-85 degrees C. From the GPC measurements, the number average molecular weights of the soluble graft copolymers produced were in range between 22000-26000 with polydispersity indices(M(w)/M(n)) in the range of 2.0-2.3.