Open-top chambers(OTC)were introduced to increase the air temperature of a sub-alpine meadow in the northwestern Yunnan Province to examine the influences of global warming on soil pH,organic matter,available nitrogen,and phosphorus content from soil depths of 0-10,10-20,20-30,and 30-40cm.After the 2-year field experiment,the average soil surface temperature increased by 1.56℃ when compared to that of the control due to the OTCs;temperature enhancement was more obvious during the winter than the summer. We found that warming had no significant effects on soil pH and available nitrogen for the 0-40cm soil layer (P>0.05).However,organic matter,available phosphorus,and urease activity of soil from the 0-10cm layer were significantly affected by the temperature enhancement when compared to that of the control(P<0.05).Organic matter content and urease activity in the warming treatment decreased by 9.6%and 38%,respectively, while available phosphorus content increased when compared to that of the control.In addition,soil pH increased with a decrease in soil depth.In contrast,the soil organic matter content,available nitrogen,and urease activity gradually decreased.