The forest ecosystem plays an important role in the global carbon cycle and is the largest carbon pool in terrestrial systems. Due to the escalating greenhouse effect, forest carbon sequestration is increasingly recognized as a vital strategy to mitigate the climate crisis. Distribution and driving factors of carbon density were examined in 156 evergreen broad-leaved forest sites in Zhejiang Province, China, employing a suite of analytical methods including Geostatistical analysis, Pearson Correlation, RF (Random Forest) and SEM (Structural Equation Modeling). Carbon density data consisted of aboveground live tree biomass carbon density, plant litter carbon density and the soil organic carbon(0~30cm) density, while driving factors consisted of both environmental and socio-economic factors. The results revealed that the average carbon density of the above-ground vegetation in the evergreen broad-leaved forest ecosystem in Zhejiang was 39.60 tC/hm2, with litter carbon density and soil organic carbon density averaging 2.18 tC/hm^2 and 85.81 tC/hm^2, respectively. These figures are comparatively lower than average level of China and those of other provinces at similar latitudes. Spatial analysis revealed that the Nugget/Sill ratios of the three carbon densities were 73.14%, 32.14%, and 58.91%, respectively, indicating moderate spatial variation and dual influence from both random and structural factors. The carbon density of the above-ground vegetation exhibited a gradual decline from west to east, while the plant litter carbon density decreased from north to south, with a smooth transition in the middle. The soil organic carbon density decreased from southwest to northeast, with marked disparities between these two regions. The main driving factors for aboveground live tree biomass carbon included canopy density, forest age and altitude. For plant litter carbon, the main driving factors were available potassium and litter thickness. And for soil organic carbon density, the main driving factors were soil available nitrogen, bulk density and altitude. Socio-economic factors had a negative impact on nearly all the carbon density components. This study provides a theoretical foundation for the conservation and enhancement of carbon sequestration capabilities for the evergreen broad-leaved forests in Zhejiang.