Abstract:A preliminary research on the sociological characteristcs, plant biomass and productivity of artificial forests of Dahurian larches at an elevation of 300--350m in the Maoershan area of Heilongjiang Provance is presented here. By using "average standard tree" and "divided storeys" methods, the biomass and production of the trees, undergrowth, living plant covers and dead branches and fallen leaves were observed.The different arrangement patterns of Dahurian larches could produce different sociological characteristcs and biological production. The estimated total mean biomass of L. gmelini plantation communities was 159.445, t/ha, the net production was 12.237t/ha·a. The total mean biomass and net production of tree layers was 149.560t/ha and 9.627t/ha·a. respectively. The biological production of the larch stands depended. on the coverage of tree layer, leaf area index(LAI), leaf biomass and efficiency of leaf. Within a certain limit, the coverage of the tree stories decreased from 90% to 70% and at the same time, the LAI of the stand increased from 3.07 to 6.66. The net production of the stand and the tree layer would increase by 105.28% and 30.89% respectively.