This contribution reports ethylene polymerization behavior of titanium complexes incorporating bis（phenoxyimine） ligands. Six phenoxy-imine Ti（IV） complexes {6-R^1-2-[CH=N（2,6-difluoro-3,5-diR^2-4-R^3Ph）]C6H30}2TiCl2 （1： R^1 = H, R^2 = H, R^3 = H; 2： R^1 = H, R^2 = H, R%3 = 4-vinylphenyl; 3： R^1 = CH3, R^2 = H, R^3 = H; 4： R^1 = CH3, R^2 = H, R^3 = 4-vinylphenyl; 5： R^1 = CH3, R^2 = F, R^3 = H; 6： R^1 = CH3, R^2 = F, R^3 = 4-vinylphenyl） have been synthesized and evaluated for ethylene polymerization using dried MAO （simplified as DMAO） as cocatalyst. An obvious catalytic heterogeneity of Cat 2 （Complex 2/DMAO） towards ethylene polymerization was observed, which was illustrated by decreased activity, multi- modal molecular weight distribution and partially improved particle morphology comparing with Cat 1. Moreover, Cat 3 exhibits ＂living＂ characteristics in the process under certain conditions （25 ~C, less than 20 min）. Otherwise, the moderate to high ethylene polymerization activity of ca. 105-106 g PE/（mol Ti＇h） and high molecular weight （Mw = 105-106） of polyethylene can be obtained by changing the skeleton structure of these complexes.
