Abstract: Depolymerization of polycarbonate(PC) in supercritical methanol was studied to develop a chemical process for waste plastics recycling.Degradation experiments were carried out in a batch-type autoclave at 230—265 ℃,7.76—9.96 MPa without any catalyst.Reaction products were analyzed by infrared spectrometer(IR), size exclusion chromatography(SEC) and gas chromatography/mass spectrometer(GC/MS).The number average molecular mass (M_n) of around 27700 for the original PC decreased to 1600 at 245 ℃ within 15 min, meanwhile monomers of PC,dimethyl carbonate (DMC) and bisphenol (A), and byproducts yielded in supercritical methanol.Percent conversion of PC and the yield of monomers and byproducts were measured;and a mechanism of methanolysis was proposed in this paper.A mathematical model based on the continuous distribution kinetics for random degradation process and secondary reactions for monomer components can be used to interpret the results.The activity energy obtained was 75.72 kJ•mol^-1 for the random degradation.