[Objective] This paper aimed to quantify the carbon content rate(CCR) of different organs of four main tree species (Picea crassifolia

Pinus tabuliformis

Populus davidiana and Ulmus glaucescens)of forest in Helan Mountain

in order to provide reference for study of carbon storage in larger scale regional forest.[Methods] CCR of above-ground part was measured using the methods of the field investigation

laboratory assay and the links of it with biomass were analyzed with corresponding coupled biomass data.[Results] The results showed that the values of CCR of above-ground part of four tree speices

Picea crassifolia

Pinus tabulaeformis

Populus davidiana and Ulmus glaucescens were 0.457 6

0.518 4

0.421 3 and 0.439 0

respectively. In a same tree species

the variation coefficients of different modules were between 1.30% and 2.57%

the values of same module were between 0.62% and 1.92%; the variation coefficients of different modules among the four different trees were between 0.89% and 5.68%

the coefficients of same module of the four different tress ranged between 4.87% and 13.37%.[Conclusion] Different tree species have different carbon CCR. The average CCR in the organs of coniferous species was higher than that in the broadleaf species. Accordingly

the average CCR in the coniferous forest was higher than that in the broadleaf forest.