The carbonyl indexes (CI) of low density polyethylen (LDPE) films containing intergrowth rare earth(La+Ce+Pr) carboxylate (RE(La+Ce+Pr)Car 3) with/without aromatic ketone (AK) mixing photosensitizers during ultraviolet (UV) photooxidation were determined by infrared spectroscopy.The effects of these photosensitizers on UV photooxidative rates and viscosity average molecular weights of LDPE films are studied by using CI as the index

and their action mechanism are discussed.Results show that RE(La+Ce+Pr)Car3 and AK mixing photosensitizers may bring about the accelerated or retarded photooxidative degradation of LDPE films to varing degrees.After both UV irradiation and long stored duration these LDPF films contining above described photosensitizers still continued the stored oxidative degradation to a certain extent.