Abstract: Hardness,softness,chemical potential and electronegativity on the active site of the HIV-1 PR are calculated by the DFT theory.The properties of the enzyme-water complex,enzyme-inhibitor complex and enzyme-inhibitor-water complex are analyzed.Based on this,charge distribution and Fukui function are calculated in terms of ABEEM.Characteristics of the active site is analyzed in detail.Our research shows that the water should be involved in the HIV-1 PR hydrolysis reaction.