Based on a systemic survey, the pyrolysis characteristics and apparent kinetics of the municipal solid waste (MSW) under different conditions were researched using a special pyrolysis reactor, which could overcome the disadvantage of thermo-gravimetric analyzer. The thermal decomposition behaviour of MSW was investigated using thermo-gravimetric (TG) analysis at rates of 4.8, 6.6, 8.4, 12.0 and 13.2 K/min. The pyrolysis characteristics of MSW were also studied in different function districts. The pyrolysis of MSW is a complex reaction process and three main stages are found according to the results. The first stage represents the degradation of cellulose and hemicellulose, with the maximum degradation rate occuring at 150 ℃-200 ℃; the second stage represents dehydrochlorination and depolymerization of intermediate products and the differential thermogravimetric (DTG) curves have shoulder peaks at about 300 ℃; the third stage is the decomposition of the residual big molecular organic substance and lignin at 400 ℃-600 ℃. Within the range of given experimental conditions, the results of non-linear fitting algorithm and experiment are in agreement with each other and the correlation coefficients are over 0.99. The kinetic characteristics are concerned with the material component and heating rate. The activation energy of reaction decreases with the increase of heating rate.