Six flavonoid compounds were isolated from the underground parts of Curcuma longa (Zingiberaceae) through repeated column chromatography. Their chemical structures were elucidated as kaempferol-3-O-${alpha}$-L-rhamnopyranosyl(1${ ightarrow}$2)-O-${alpha}$-L-rhamnopyranoside (1), quercetin-3-O-${alpha}$-L-rhamnopyranosyl(1${ ightarrow}$2)-O-${alpha}$-L-rhamnopyranoside (2), quercetin-3-O-${eta}$-Dglucopyranoside-7-O-${alpha}$-L-rhamnopyranoside (3), kaempferol-3-O-${alpha}$-L-rhamnopyranoside (4), quercetin-3-O-${alpha}$-L-rhamnopyranoside (5), and quercetin (6), respectively, by spectroscopic analysis. These compounds were isolated for the first time from this plant.