This study selected Picea crassifolia forest which lived at altitudes of 2 900~3 000 m in pailugou catchment of Qilian Mountains as objects. By field investigation and laboratory analysis, the distribution characteristics of soil physicochemical properties and enzyme activities along the altitudinal gradients were studied. The relationships between soil physicochemical properties and soil enzyme activities were also analyzed. The results showed that:(1) With the increased altitudes, soil water contents, as well organic matter, total nitrogen and available potassium contents increased gradually; but soil bulk densities, pH values and total potassium contents decreased gradually; total phosphorus contents decreased at first and then increased, available phosphorus contents had not significant variation. (2) With the increased altitudes, the activities of invertase and alkaline phosphatase showed an increasing trend generally, the activities of urease decreased at first and then increased generally, and the activities of protease changed a little and had no significant difference (P>0.05). (3) Soil enzyme activities were closely related to soil organic matter, nitrogen, phosphorus and potassium contents, among which sucrase, urease and protease activities were significantly correlated with soil total nitrogen, total potassium and available potassium contents (P<0.05). (4) There existed significantly correlations among four enzyme activities, indicating that enzymatic reaction had specificity and commonality.