In order to study the characteristics of soil microbial functional diversity in mid-subtropical forest and their changes along an altitudinal gradient, Biolog microplate analysis was used to investigate into the functional diversity of microbial communities under three vegetation zones in the National Natural Reserve of Maoer Mountain. The vegetation zones were evergreen broad-leaved forest (EBF), deciduous broad-leaved forest (DBF) and coniferous and broad-leaved forest (CBF). The results showed that the functional diversities of soil microbial communities were significantly different in different altitudes. The average well color development (AWCD) of soil microbial community which reflects the utilization of sole carbon source is taken as an important indicator of soil microbial activity and functional diversity. The AWCDs in different vegetation belts increased with culturing time and decreased gradually with the altitude in an order of EBF > DBF > CBF. Soil physical-chemical properties in different vegetation belts along an elevation gradient were significantly different. Soil pH and total K were monotonic decreasing while soil water content was monotonic increasing. Shannon diversity and richness indexes of microbial communities in EBF were the highest, followed by DBF and CBF. No significant differences in evenness index of microbial communities were found in different altitudes. Carbon source utilization was significantly different in different altitudes, where EBF and CBF were the highest and lowest, respectively. Amino acids, amines, and esters were the main carbon sources. Two factors of carbon sources were identified using the principal component analysis, explaining 40.42% and 15.97% of the total variances, respectively. The two factors were separated mainly due to carbon sources of esters, amines, and amino acids. Correlation analysis was used to evaluate the correlation of soil physical-chemical properties and microbial community functional diversity. The results showed that the Shannon diversity indexes of the three vegetation zones were positively correlated with TK at the most statistically significant level of 0.01, negatively correlated with soil water content at the most statistically significant level of 0.01, and negatively correlated with TOC, TN, AN, and AP at significant levels of 0.01 or 0.05. The correlation between soil physical-chemical properties and microbial community functional Shannon index was significant. We conclude that soil physical-chemical properties and microbial community functional diversity along an altitudinal gradient showed some regularity. Different TK and water contents in soil could be the main reasons for the variation of microbial community diversity in the soils under the vegetation zones.