［Objective］Accurate assessment of the value，distribution characteristics，composition and influencing factors of regional forest carbon storage and sequestration is an important basis for scientific formulation of forest management and corresponding regulation policies.［Methods］Ecotype counties belonging to typical subtropical forest areas were selected as the study area. A total of 97 sample plots with different tree species and age groups were selected to carry out field measurement of above-ground and below-ground carbon storage and sequestration， analyze the composition of carbon storage and the relationship between carbon storage and site factors，and compare the measured carbon sequestration values with those calculated by the CASA model. The aim was to provide a reference for the assessment of carbon storage and sequestration in typical subtropical forests.［Results］1）In 2020， the average forest carbon density，total carbon storage，and total carbon sequestration of vegetation layer in the study area were 158.05 t/hm²，4.07 ×10⁷ t and 28.41×10⁵ t/a，respectively. Betula forests had the highest forest carbon density，Hardwood forests and other evergreen broadleaf forests had the highest forest carbon storage and vegetation carbon sequestration. Among age groups，young forests had the highest carbon storage. The overall distribution of carbon density was ranked in the order of soil layer（56.19%）>vegetation layer（42.94%）>litter layer（0.87%）. 2）Among the site factors，soil thickness was significantly positively correlated with soil carbon density and negatively correlated with litter density. 3）Except for shrublands，the CASA model significantly underestimated carbon sequestration compared to the measured values from the sample plots，with the measured values being 96.49% higher than the model estimates.［Conclusion］In typical subtropical forests，Betula has a significant advantage in vegetation carbon density. Soil layer carbon storage is the largest part of forest carbon storage，and soil layer thickness is the most important driving factor affecting soil carbon density and litter carbon density. Additionally，except for shrublands，the model calculations underestimated the forest carbon sequestration in the study area.