Fire-resistance forest belts can effectively prevent large area's fire damage. In this paper the components and flammability of the leaves, twigs and bark of 12 tree species in the mountain area of Daguishan Guangxi-Zhuang autonomous region have been tested and analyzed in the laboratory. The test and analysis indicate the results as f following:( l) For all the tree species, the leaf's fire-resistance is much weaker than that of twigs and bark, and the broad leaves are stronger than those of conifers in fire-resistance .2 ) Heat value, moisture, ignition point and ash content are main indexes to affect fire-resistance. Heat value relates to lignin content and benzene-ethanol extractive content linearly. (3) Of all the 12 tree species, Schima surperba, Castanopsis hystrix, Myria ruba have strongest resistance to fire; Machiluis pauhoi, Mytilaria laosensis, Michelia Macclurei, schima, sp. are relatively strong in fire-resistance, and Cunninghamia lancedata and Pinus massniana the least strong in fire-resistance.