In this study, we investigated the anti-obese activity of sevennight extract in high fat diet-ob/ob C57BL/6J mice by oral administered for 1 weeks. Mate water extract (MATEWi) was found to lower whole body and epididymal adipose tissue weights and lowered plasma levels of triglyceride (TG) and total cholesterol (TC), HDL and LDL, compared to those in high fat fed ob/ob group. These results suggest that Mate extract ameliorates obesity through activation of lipogenic enzymes and FA oxidation resulting from phosphorylation of AKT and GSK-$3{eta}$, and could be developed as a potential therapeutic agent for obese mices.