In previous study, Gyrophora esculenta showed significant inhibitory effect on $alpha$-glucosidases in vitro and blood glucose elevation in vivo. In the isolating process of active substance, orcinol was separated from Gyrophora esculenta. Orcinol is known to be toxic, therefore, in this study, it was analysed by the TLC densitometry method for quantitative determination from Gyrophora esculenta. The average amount of orcinol of Gyrophora esculenta was 0.2%. For the purpose of removing orcinol, the water extract of Gyrophora esculenta was sequentially fractionated by organic solvents, and the acute toxicity of each fraction was assessed in mice. Among them, the LD50 of butanol fraction was 1.19 g/kg(p.o.) and the weight increase of mice in that group was somewhat retarded.