Abstract: In order to understand the pyrolysis characteristics of 3 main afforestation tree species of Alnus nepalensis, Pinus armandii and P.yunnanensis in central Yunnan, the 3 kinds of bark were subjected to thermogravimetric test at 10 ℃/min, 20 ℃/min and 30 ℃/min. The kinetic parameters were calculated and the kinetic equation was established. The analysis showed that the order of weight loss rate was A.nepalensis > P.armandii > P.yunnanensis when the pyrolysis temperature in a range of 25-800 ℃. The TG curves of the 3 barks were very similar, followed the same pyrolysis mechanism. The combustion process of the 3 kinds of bark can be described by first-order kinetics equation and activation energy order from small to large was P.armandii, P.yunnanensis and A.nepalensis. It indicated that A.nepalensis bark has good fireproof performance and poor in P.armandii bark.