As global climate change continues to accelerate, biological carbon storage, which plays an important ecological role in forest ecosystems, have a very significant effect on carbon emissions and carbon sinks and also play an important role in carbon cycle. Forest ecosystems, as a principal component of terrestrial ecosystems, are the world' s largest carbon (C) pool and C sink. The amount of C storage in vegetation plays an important role in global C cycle and C balance. Scientifically and effectively measuring biological C storage provides important data needed for understanding the significance of forest biomass in the C cycle as well as for understanding climate change. This study analyzed biological C storage in typical forest types in the Daxing'anling Mountains in Heilongjiang Province, China, using forest inventory data and geographic information system technology. Five typical forest types in the Daxing'anling Mountains were studied using various age groups and different forest components (trees, shrubs, herbs and litter), specifically Larix gmelinii, Betula platyphylla, Pinus sylvestris var. mongolica, Quercus mongolica, and Populus davidiana forests. For each forest type, tree, understory shrub, herb, and litter layers were surveyed to determine and measure biomass per unit area, C biomass, and C forest stocks. At the stand level, age groups were classified so that estimates of forest biomass and forest C stocks in the study area could be calculated. The biomasses in different age groups of the five typical forest types in the Daxing'anling Mountains including young forest, middle-aged forest, near mature forest, and mature forest were analyzed:. Biomass per unit area of Larix gmelinii forests for these four age groups was 31.00 t/hm², 101.29 t/hm², 188.46 t/hm², and 215.23 t/hm², respectively. Similarly, the same four age groups of Betula platyphylla forests held 33.13 t/hm², 65.64 t/hm², 88.67 t/hm², and 136.38 t/hm² of biomass per unit area; the four age groups of Pinus sylvestris var. mongolica forests had 61.22 t/hm², 120.30 t/hm², 179.10 t/hm², and 229.43 t/hm² of biomass per unit area; the four age groups of Quercus mongolica forests had 23.89 t/hm², 25.00 t/hm², 70.70 t/hm², and 126.20 t/hm² of biomass per unit area; and, the four age groups of Populus davidiana forests had 47.28 t/hm², 61.71 t/hm², 91.16 t/hm², and 135.53 t/hm² of biomass per unit area, respectively. Our study determined that biological C storage of the five typical forest types in different age groups varied widely in the Daxing'anling Mountains. C storage per unit area for young forest, middle-aged forest, near mature forest, and mature forest listed in respective order, for each forest type are as follows: 15.20 t/hm², 50.96 t/hm², 95.80 t/hm², and 109.33t/hm² for Larix gmelinii forests; 15.36 t/hm², 30.67 t/hm², 41.62 t/hm², and 64.35t/hm² for Betula platyphylla forests; 29.89 t/hm², 59.92 t/hm², 90.01 t/hm², and 117.08 t/hm² for Pinus sylvestris var. mongolica forests; 11.17 t/hm², 11.90 t/hm², 34.94 t/hm², and 59.49 t/hm² for Quercus mongolica forests; and, 21.81 t/hm², 28.58 t/hm², 42.84 t/hm², and 64.39 t/hm² for Populus davidiana forests. These results show that biological C stocks in the Daxing'anling Mountains play an important role in the C cycle and regional C balance. Different age groups in five typical forest types serve as forest C stocks based on forest biological age with the C stock increasing with forest growth and aging. Nevertheless, the type of forest C sink function varies in different forest types, although the same types of large differences were observed in biological C forest reserves in stands of different ages among the five forest types. Because most of the growth in the five major forest types occurs in young and middle-aged forest, forests at these ages have a great potential to provide C storage in forest vegetation. This significant C sink function is further enhanced in the Daxing'anling Mountains area with the development and restoration of areas designed to provide specific ecological services including important role as C sinks. In order to achieve sustainable development of these forest ecosystem, a defined C management strategy should be developed that includes an increasing use of these potential C sinks and simultaneously includes plans for the management of economic growth. Our findings are important for land managers and other stakeholders who need to gain correct understanding of biological effects of forest C stocks and C balance as part of regional ecological analysis. Our results also provide reference data related to the full effect of forest plantations as C sinks as it relates to future silvicultural and reforestation activities.