Abstract: A thermogravimetric system was designed, in which a large amount of sample (about 10 g) can be examined. The pyrolysis characteristics of the mixture of typical organic components (paper, wood, fibre, plastic, rubber and food residue) of MSW (municipal solid waste) were studied. The pyrolysis kinetics model, which consists of several parallel reactions, was obtained using the least square algorithms. The results calculated by the model have good agreement with the experimental ones. Based on these results, the interactions and nonlinear phenomena in pyrolysis of the mixture were analyzed. The results show that the pyrolysis kinetics model of the mixture of typical organic components of MSW consists of 2～4 parallel reactions. Sometimes parallel reactions merge during pyrolysis. Heat effect and the mixing proportion have remarkable effect on the overall pyrolysis characteristics of the mixture.