Abstract: This paper uses woods,underground vegetation,litters and coarse woody debris of types of Inner Mongolia Daxinganling virgin forests and their four kinds of carbon library layers and various organs of trees to research the carbon density and storage and also the method of combining field sampling and indoor experimental analysis.The 5 kinds of virgin forest types are Ledum palustre-Larix gmelinii virgin forest,Rhododendra-Larix gmelinii virgin forest,Betula exilis-Larix gmelinii virgin forest,Grass-Larix gmelinii virgin forest,Bryaceae-Larix gmelinii virgin forest.The result shows that (1)among the trees,the sequence of different organ carbon content of Larix gmelinii is bark,leaf,trunk,branch and root,accounting for 54.89％,21.98％,10.76％,9.65％ and 2.72％ of the tree’s total carbon density.(2)The carbon density sequence of the 5 kinds of forest stands is:Grass-Larix gmelinii virgin forest(83.992 4 t/hm²),Rhododendra-Larix gmelinii virgin forest(54.788 8 t/hm²),Bryaceae-Larix gmelinii virgin forest(50.612 1 t/hm²),Ledum palustre-Larix gmelinii virgin forest(49.396 4 t/hm²) and Betula exilis-Larix gmelinii virgin forest(48.587 8 t/hm²) and the mean carbon density of the Larix gmelinii forest ecological system is 57.475 5 t/hm².(3) In the research area,the total carbon storage of the Larix gmelinii forest ecological system is 2.840 3 TgC and the carbon library space distribution sequence is tree layer (2.054 3 TgC),falling object layer(0.349 5 TgC),understory vegetation layer (0.231 6 TgC) and galleries woody debris(0.204 9 TgC).The total carbon storage in the ecological system is 72.33%,12.31%,8.15% and 7.21%。

Key words: Larix gmelinii virgin forest, carbon density, carbon storage