Group 4 non-metallocene catalyst is an important type of catalyst for olefin polymerization. It not only possesses advantages of high catalytic activity and wide scope of comonomers

but also can obtain poly-olefins with controllable structure. Besides

the synthesis and cost of this type of catalyst are easier and lower compared with metallocene catalyst. These advantages help group 4 non-metallocene catalyst enriching the catalyst structure and developing new polyolefin products. The research process of group 4 non-metallocene catalyst in recent ten years has been reviewed according to the structure of ligands. The structure characteristics and catalytic performance in olefin homo- and copolymerization of this kind of catalyst has been discussed

focusing on the electronic and steric effect within ligands on the catalytic activity of complexes and properties of resultant polyolefins. Finally

some suggestions on the future development of the related fields are put forward.