Abstract:In order to study the distribution characteristics of organic carbon and its components in forest soils under different vegetation types in Shandong Province, forest soils were collected in different soil layers (0–20 and 20–40cm) under three vegetation types of Pinus thunbergii, Cupressus funebris and mixed conifer forest in Shandong Province, and the changes in soil organic carbon (SOC), soil dissolved carbon (DOC), easily oxidizable organic carbon (EOC) and particulate organic carbon (POC) were analyzed and compared. The results showed that:1) SOC contents under Pinus thunbergii, Cupressus funebris and mixed coniferous forest in the 0–40 cm soil layer varied with 4.35–15.04, 5.72–34.87 and 3.71–10.72 g/kg, respectively, and Cupressus funebris had the highest SOC content in each soil layer; 2) SOC and its components differed somewhat under different vegetation types, with SOC and POC contents were in order of Cupressus funebris > mixed coniferous forests and Pinus thunbergii, DOC contents in order of Cupressus funebris> mixed coniferous forests > Pinus thunbergii in the upper and lower soil layers, and EOC contents in order of mixed coniferous forests > Cupressus funebris and Pinus thunbergii; 3) Except for DOC in Pinus thunbergii, SOC, EOC, EOC and POC contents of the remaining vegetation types decreased with the increase of soil depth; 4) The correlation analysis showed that SOC was significantly positively correlated with POC (P<0.01), and the other carbon fractions had no significant correlation, and the redundancy analysis showed that soil carbon fractions were greatly affected by soil physicochemical factors, with soil carbon fractions significantly correlated total nitrogen and rapid available potassium (P<0.01), and annual precipitation and pH(P<0.05). In conclusion, there was variability among organic carbon and its active fractions under soils of Pinus thunbergii, Cupressus funebris, and mixed conifer forest, all carbon fractions except EOC showed the highest content in Cupressus funebris, while EOC content is highest in the mixed conifer forest, SOC and its components are influenced by vegetation types and soil depth with epimerization phenomenon.