Soil samples under seven different vegetation types were collected from Guiyang city and thirteen soil characteristics were measured to quantify the effects of soil characteristics on microbial function. Results showed that 77.9% of the variation in substrate utilization and total variation in functional diversity could be explained by soil indices characteristics, among which soil pH, Olsen-P, available potassium, soil organic carbon, hydrolysable nitrogen and dissolved organic carbon explained 48.4%, 15.9％, 5.9%, 5.7%, 1.6% and 0.4% of the variation in substrate utilization respectively, while Olsen-P, available potassium, soil organic carbon, total nitrogen explained 67.4%, 27.7％, 4.7% and 0.2% of the variation in functional diversity respectively, which suggested microbial function measured by Biolog GN plate was mostly determined by soil characteristics.