|| The definite diagnosis of persimmon phytobezoar (i.e., diospyrobezoar) is often accomplished by a component analysis using infrared spectroscopy. However, no studies have been conducted to investigate which substance is the best as a standard for the component analysis. Here we analyzed tannic acid, Japanese persimmon (kaki), fermented persimmon extract (kaki-shibu), conventional dried persimmon, and dried persimmon smoked in sulfur (ampo-kaki) by infrared spectroscopy to determine which would be optimal as a component analysis standard. The spectrum between 1,600 to 600cm－1 of a persimmon phytobezoar was quite similar to the spectrum of kaki-shibu rather than that of tannic acid. Consequently, we conclude that kaki-shibu should be used as a standard for infrared spectroscopy analyses of persimmon phytobezoars.