Abstract: The high-density polyethylene (PEHD) resin was fractionated by different methods, and its branch structure and distribution were investigated. A three-dimensional relationship graph for the short-chain branching content, elution temperature and molecular weight was established by a combination of temperature rising elution fractionation and other cross-fractionation methods, which well reflected the branch-structural distribution characteristics of PE-HD. The results indicated that the PE-HD resin was composed of four parts including a low molecular wax containing a certain amount of branch structure, a part of linear low-density polyethylene with larger short-chain branching numbers, a part of high-density polyethylene with small short-chain branching numbers, and the linear polyethylene almost without any branching chains. It was also found that the fraction of the linear low-density polyethylene increased with an increase of relative molecular weight, whereas the part of the high-density one kept a uniform molecular weight distribution.