Forest carbon stock is an important proportion of the carbon in terrestrial ecosystems, playingan important role in global carbon cycle. Forest ecosystems fix carbon through photosynthesis and mainly allocate to three organic carbon pools: live plant carbon pool, soil organic carbon pool and dead plant carbon pool. However, the threepools show great spatial-temporalvariationsand cause a lot of uncertainty in understanding of the mechanisms of forest carbon storage. Forest biomass closely related to forest carbon stocks, despite some clear global and regional patterns, little agreement has been reached regarding the ecological drivers for these patterns and the extent to which they can be extrapolated to large scale. Therefore, how ecological factors influenceforest carbon storage and the relationships between these factorsare two critical questions. In this paper, (1) we discussedthe effects of climate,soil, topography andbiotic onabove-ground biomass, respectively. (2)Thenwe analyzedthe direct or indirect relationship between climates, soil, topographic and stand factorswhen AGB was considered. (3)We introduced two new methods,hierarchical model and habitat classification, to evaluatethe relationships between AGB and ecological factors. The aim of this paper is toenhance our understanding of how ecological factors influencing forest carbon storage.