unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 4 Methylthio 3 butenyl isothiocyanate (MTBI) is a pungent bio active constituent found in daikon. However, MTBI is immediately hydrolyzed to 3 hydroxy methylene 2 thioxopyrrolidine in grated daikon. In this study, we evaluated whether MTBI in grated daikon complexed with α cyclodextrin (αCD) has anti obesity effects in mice. C57BL/6J mice were fed a normal diet (normal group), high fat diet (HFD, control group), HFD with αCD (αCD group), or HFD with MTBI αCD (MTBI αCD group) for 16 weeks. The results showed that the final body weight, epididymal white adipose tissue weight, and plasma triglyceride and total cholesterol levels were significantly lower in the MTBI αCD group than in the control group. The cell size in epididymal adipose tissue was significantly smaller and the accumulation of lipids in the liver was significantly lower in the MTBI αCD group than in the control group. Furthermore, real time polymerase chain reaction showed that the mRNA expression level of tumor necrosis factor alpha was suppressed in the MTBI αCD group. We also observed low superoxide dismutase activity in the MTBI αCD group, possibly because MTBI αCD has the potential to resist HFD induced oxida tive injury. In conclusion, MTBI αCD exerted anti inflammation and antioxidant effects to suppress lipid accumulation in epididymal adipose tissue and the liver. These effects then prevented HFD induced obesity in mice.