The crystallization and melting behavior of mellocene-catalized branched and linear polyethylenes of low molecular weight was studied．It was found that the crystalline lattice of branched polyethylene is larger than that of linear polyethylene because of the existence of branched chains．The melting behavior of branched polyethylene is similar to that of linear polyethylene since the branched chains can not enter the lattice．However．the crystalline behavior of low molecular weight branched polyethylene is the same as that of high molecular weight linear polyethylene

but different with that of low molecular weigh linear polyethylene．Kinetics theory analysis evidenced that the transition temperature of growth regime of the branched polyethylene is about 20℃ lower than that of linear polyethylene with the same molecular weight.It may be attributed to the existence of short branched chains．