Non-metallocene catalysts containing [N, Si, N, P]-type ligands based on diphenyl phosphorus-phenylamine and their derivatives were synthesized and characterized by H(C-13) NMR, ESI-MS and micro analysis. They were able to catalyze copolymerization of ethylene with N-acetyl-O-(hex-5-enyl)-L-tyrosine ethyl ester after activated by methylaluminoxane (MAO). Effects of transition metal atoms (Ti, Zr and Hf), ligand structures and polymerization conditions were investigated. The structures and properties of the obtained polymers were characterized by FT-IR, C-13 NMR, GPC and DSC. The results indicated that the obtained copolymers had high weight average molecular weight of 2.70 x 10(5) g/mol and high comonomer incorporation rate of 23.07 wt% within the copolymer chain. The melting temperature of the copolymer was up to 138.6 degrees C higher than that of the polyethylene.