Abstract: sample plots of Larix principis-rupprechtii plantation were investigated in Wutaishan Mountain region. Biomass of organs and content of nutrient elements of averagetrees were measured in the sample plots. Regression models of tree biomass and DBH wereselected.Annual biomass increment response was simulated according to the logistics equation. The results were as follows. BiO mass of tree and annual forest increment response isshowed by a parabola,its peak is at the age of 24;the peak of the amount of net photosyn-thesis rate of needle(400g/m2)is at the age of 18.When this larch plantation is of 15-year-old,the order of accumulation of nutrient elements is as follows:the amount of the nutrientelement accumulated(including N、Ca、K、Mg、P) are 888.91 kg/hm2,among which N 406.86 ks/hm2(including 54.35 kg/hm2 in stems and 214.56 kg/hm2 in needles).Besides,thereare N 3.5 kg in 1 ton of dry matter and N 4.6 kg in 1 m3 of wood,but only 0.611 kg of N was in 1 m3stem(accounting for 13.36% of the total),the rest of the N was in the branches,leaves,barks and roots.