Abstract: The chemical species of platinum group elements in some upper mantle derived xenoliths from Eastern China are studied by molecular activation analysis,in which the chemical stepwise dissolution,nickel fire assay preconcentration and neutron activation analysis are jointly applied. The weighted sums of platinum group elements in 6 phases are in agreement with their total contents.The distribution patterns of platinum group elements in sulphides show that sulphide segregation is one of the important mechanisms for the fractionation of platinum group elements in upper mantle derived material during partial melting.