As a significant early phase of diabetes, Impaired Glucose Tolerance(IGT) has seen a surging outbreak recently. The article discusses the epidemic tendency and risk factors, suggest effective prevention through health education and life style adjustment. Considering IGT is characteristically accompanied by phlegm, dampness, heat and stagnancy, a comprehensive therapy aiming at phlegm-resolving, heat-clearing, spleen-invigorating, liver soothing, blood-activating and collateral dredging, such as Modified Xiao Xianxiong Tang can lower blood sugar, thus treat IGT.