A novel non metallocene supported catalyst,CpTi(dbm) Cl 2/MgCl 2 was synthesized in situ via reaction between CpTi(dbm)Cl 2 an d BuMgCl in heptane.The surface area,pore volume and crystal structure of the su pported catalyst and MgCl 2(in situ) which was obtained by reaction of Mg a nd BuCl were characterized by BET and XRD methods,respectively.The surface area and pore volume of MgCl 2(in situ) are higher than those of normal MgCl 2,and the s urface area and pore volume of the supported catalyst are also high.The crystal structure of the supported catalyst is amorphous,which is similar to that of MgC l 2(in situ).Ethylene polymerization with MAO or AlR 3 was investigated,w hich indicates that the activity does not decrease while AlR 3 was used as co catalyst instead of MAO,so MAO can be absent in both the catalyst preparation an d et hylene polymerization processes.The catalytic activity can be as high as 3 06× 10+6gPE/molTi·h with triisobutyl aluminium(Ti BA) as co|catalyst when polymerization tem perature is 80℃,and Al/Ti molar ratio is 200. A novel non metallocene supported catalyst, CpTi (dbm) Cl 2 / MgCl 2 was synthesized in situ via reaction between CpTi (dbm) Cl 2 an d BuMgCl in heptane. The surface area, pore volume and crystal structure of the supported catalyst and MgCl 2 (in situ) which was obtained by reaction of Mg a nd BuCl were characterized by BET and XRD methods, respectively. The surface area and pore volume of MgCl 2 (in situ) are higher than those of normal MgCl 2, and the s urface area and pore volume of the supported catalyst are also high. The crystal structure of the supported catalyst is amorphous, which is similar to that of MgCl 2 (in situ) .Ethylene polymerization with MAO or AlR 3 was investigated, w hich indicates that the activity does not decrease while AlR 3 was used as a co-catalyst instead of MAO, so MAO can be absent in both the catalyst preparation an d et hylene polymerization processes. The catalytic activity can as high as 3 06 × 10 + 6gPE / molTi · h with triisobutyl aluminum (Ti BA) as co | catalyst when polymerization tem perature is 80 ° C, and Al / Ti molar ratio is 200.