Abstract: Taking the litter in the 6 main forest types of Huangsongpu forest farm of Changbai Mountain as the object, the combustibility of litter on the surface of Changbai Mountain forest area is studied. Sample plots were set up in 6 main forest types of Huangsongpu plantation in Changbai Mountain, including birch forest, coniferous mixed forest, needle- leaved mixed forest, larch forest, broad-leaved mixed forest and poplar forest. By means of field investigation and mixed sampling, experimental materials were collected to measure the speed, temperature and mass change of fire spread in the combustion bed. By changing wind speed, slope and slope direction, the effects of different conditions on fire behavior, fire spreading speed and burn rate were studied. The experimental results show that the fire intensity of surface litters in the order from large to small were birch forest, coniferous mixed forest, coniferous mixed forest, larch forest, broad-leaved mixed forest and poplar forest; The fire intensity of birch forest is the largest, 460.23 kW/m, and the fire intensity of poplar forest is the smallest, 367.09 kW/ m. The greater the wind speed is, the greater the spreading speed of surface litter is; when the wind speed is 6 m/ s, the average temperature of the combustion process is the highest and the burning loss rate is the highest; When the wind speed is less than 2 m/s or greater than 8 m/s, the fuel cannot be completely burned out.; When the slope of the uphill fire increases, the fire spreading speed of the surface litter increases, and the burning loss rate decreases ; When the slope of the downhill fire increases, the fire spreading rate of the surface litter decreases and the burning loss rate increases. 

Key words:  , Changbai Mountain, surface litter, fire behavior, fire spread, burning loss rate