The anti-inflammatory effect on contact dermatitis of the water solubilized 1′-Acetoxychavicol Acetate (ACA) by complexation with β-1,3-glucan isolated form Aureobasidium pullulans black yeast is reported. It is well-known that ACA possesses a function to inhibit the activation of NF-κB by which genes encoding proinflammatory cytokines, chemokines, and growth factors are regulated. However, because ACA is quite insoluble in water, its usefulness has been extremely limited. On the other hand, a triple-helical polysaccharide β-1,3-glucan can include hydrophobic compounds into intrastrand hydrophobic cavity and solubilize poorly water-soluble compounds. In this study, solubilization of ACA by complexation with highly branched β-1,3-glucan was achieved. The effect of anti-inflammatory response of water-soluble ACA complex with β-1,3-glucan was confirmed in vitro and in vivo.