We reported the seasonal variations of flavonoid compounds in leaves of four bamboo species, i.e., Phyllostachys heterocycla, Pleioblastus amaru, Dendrocalamopsis oldhami and Acidosasa edulis. The contents of total flavonoids (TF), independent of bamboo species, increased from 3 to 13.1 mg per gram of dry leaf weight as leaves developed. TF showed an upward trending from autumn to summer. For each species, the levels of major flavonoid compounds in leaves showed a similar seasonal change with that of TF. The total types of flavonoid compounds varied among the four bamboo species: Phyllostachys heterocycla contained more mono-C-glycosylflavones, Pleioblastus amaru contained more O,C-diglycosylflavones and di-C-glycosylflavones, di-C-glycosylflavones were rich in Dendrocalamopsis oldhami, and O,C-diglycosylflavones were rich in Acidosasa edulis.