Hovenia dulcis has been reported to have various pharmacological activities, but most studies were done with its fruits. However, from an economic point of view, the use of discarded leaves and branches as by-products is very valuable. In this study, thein vitro andin vivo anti-obesity activities of Hovenia dulcis branch extract (HDB) were investigated to evaluate the applicability of HDB as an anti-obesity agent. In differentiated 3T3-L1 cells, HDB inhibited lipid droplet accumulation. And HDB downregulated CEBPα, PPARγ, and perilipin-1, and upregulated ATGL, p-HSL, HSL, p-AMPK, UCP-1, PGC-1α, PRDM16, LC3-II, and p62/SQSTM1. In addition, HDB increased free glycerol content. In HFD-induced obese mice, HDB reduced body weight and total fat weight. In addition, HDB decreased blood LDL-cholesterol, blood total cholesterol, and blood triglyceride. These results indicate that HDB has anti-obesity activity and HDB can be used as a healthy functional food agent for weight reduction.