Metallic organic compounds of iron, stannum and manganese were introduced into lowdensity polyethylene as catalysts of degradation at low temperatures. The mechanical properties, viscosity-average molecular weight of polyethylene and the hydropeoxide concentration in the matrix were measured, It was shown that at 70℃ the adopted additives can catalyze the degradation of polyethylene efficeienty. After 60 day's aging, most of the samples became very fragile, and their molecular weight decreased in large scales. The relationship between molecular weght and hydroperoxide concentration, as well as the mode of the degrading behavior of the prepared matries, was also discussed.