The metal catalysts based on phosphinoarenesulfonate (PO) ligand display interesting olefin polymerization properties, which not only polymerize ethylene to linear polyethylene, but also copolymerize ethylene with polar vinyl monomers or CO to functional linear copolymers. The structural features of PO ligand and the novel polymerization reactions initiated by (PO)Pd(II) complexes are assumed. Then the application of (PO)Ni(II) catalysts in the copolymerization of ethylene with polar monomers, as well as the rare catalytic properties of Pd(II), Ru(IV) catalysts based on phosphine-bis(arenesulfonate) (OPO) ligands are reviewed. At last, the influence of PO ligand structural features such as symmetry, flexibility, steric effect in axial direction, as well as the pure electronic effect on the insertion and polymerization reactivity of PO metal catalyst are explored, at the same time, the catalytic reaction mechanism is also studied.