Two new flavonoid glycosides, coptiside I, mp 190-191°, C₄₆H₅₈O₂₇·4H₂O and coptiside II, mp 243-244°, C₂₁H₂₀O₁₁·21/2H₂O, were isolated from the leaves of Coptis japonica MAKINO. The structure of coptiside I was established to be acacetin-7-O-β-D-glucopyranosyl-(1-2)-O-β-D-glucopyranosyl-(1-2)-O-[2, 4-O-diacetyl-α-L-rhamnopyranosyl-(1-6)]-3-O-acetyl-β-D-glucopyranoside and of coptiside II was to be 7-O-β-D-galactopyranosylquercetin on the basis of chemical and spectral data.