Electron-induced crosslinking of polypropylene with the addition of hydrogen-donating hydrocarbons produced from petroleum (HHAP) together with A-TMPT (trimethylpropanetriacrylate) was studied, and the following results were obtained : (1) Effective crosslinking was achieved at lower doses under 10 kGy. (2) HHAP functions as an effective radical scavenger to suppress scissions. (3) Distinguished improvements in properties such as elongation and heat distortion temperature were achieved by the irradiation. (4) Distinct diminution in melt flow rate and evident increase in average molecular weight with the irradiation at lower doses were observed. (5) It was confirmed that the oxidative degradation during mixing and molding was noticeably inhibited by the addition of HHAP. This effect as an antioxidant during these procedures along with the irradiation seems to be a cause to promote crosslinks. These effects are attributable to the high radical scavenging effects of HHAP and its pure hydrocarbon constitution without functional groups containing heteroatoms.