Abstract: Analysis of 16 flavonoids and 3 other phenols in 177 samples of the genus Rhododendron was carried out by HPTLC silica gel plate-stepwise development and polyamide thin layer. The result reveals that the presence of monoglycosides of quercetin is a general character of flavonoids in the Chinese rhododendrons; some taxa are characterized by presence or absence of certain glycosides; although myricetin, and gossypetin are generally rare in this genus, they are concentrated in some taxa, and therefore they are valuable in chemotaxonomy. The significance of quantitative and semi-quantitative assessment of chem-ical characters for chemotaxonomy of Rhododendron is also discussed.

Key words: Rhododendron L, Flavonoids, Flavonol glycosides, Chemotaxonomy, Quantitative analysis