Effect of a new pesticide, acetamiprid, on biological activity in upland soil was studied through analysis of soil enzyme activities and soil respiration.The results show that acetamiprid obviously affected soil respiration and phosphatase activity, and the higher the concentration was, the stronger the inhibitive effect was.The activity of dehydrogenase was enhanced in two weeks after acetamiprid application Variance of urease and catalase showed no distinct relationship with the application rate.The activity of proteinase was not significantly affected within the first two weeks after acetamiprid application but was from the 4th week.