Mei (Prunus mume Sieb. et Zucc.) flower is one of the candidates for the national flower of the People's Republic of China. Several major anthocyanins from the flowers of P. mume Sieb. et Zucc. were isolated with MeOH-HOAc-water (10:1:9, v/v), and purified by paper chromatography and subsequent column chromatography. Specific chemical reactions, chromatographic and spectroscopic analyses indicated that the anthocyanins in `Nanjing Hongxu' (Nanjing red-bearded) were cyanidin 3-O-(6'-O-α-rhamnopyranosyl-β-glucopyranoside) and cyanidin 3-O-(6'-O-galloyl-3'-O-β-glucopyranosyl-β-glucopyranoside). Anthocyanins in `Nanjing Hong' (Nanjing red) were cyanidin 3-O-(6'-O-α-rhamnopyranosyl-β-glucopyranoside), cyanidin 3-O-(6'-O-galloyl-β-glucopyranoside) and cyanidin 3-O-(6'-O-E-feruloyl-βglucopyranoside). In addition to contributing to the blue flower color, the anthocyanins may improve the ability of the two cultivars to survive at low temperatures.