Abstract: According to the measure and research on the biomass of natural secondary Quercus liaotungensis stand in Lixian county at the upper reaches of Minjiang river,the results are as follows:(1)natural secondary Quercus liaotungensis stand biomass reaches 488.49 t/hm2,in which the arborous layer biomass is occupying 99.22% of the total and the sequence of other layers is:litter layer>shrub layer>moss layer>herb layer;(2)In the arborous layer biomass,the order of different organs is:stemwood>branch>root>bark>leaf>fruit,and that of root biomass is:root neck>thick root>middle root>thin root;(3)In the shrub layer,the order of different parts is:root>stemwood and branch>leaf,that in the herb layer is:root>the aboveground parts,while that in the litter layer is:fallen leaves>deadwood>fallen nuts.In addition,the vertical distribution of Quercus liaotungensis biomass has also been studied.