Defatted methanol extract of the aerial part of Rhododendron anthopogon (Ericaceae) afforded Ranhuadujuanine-A (I), Cannabioricylolic acid (II), Umbliferrne (III) and Betulin (IV). The structures of the isolated compounds were confirmed by elemental analysis i.e. 1H, 13C NMR, IR and MS spectroscopy. In vitro antioxidant activity for all the compounds evaluated where ascorbic acid (vitamin C) treated as standard. All the analysis was made with the use of UV-Visible spectrophotometer. Result of the study suggested that all the compounds showed effective efficacy for antioxidant properties in concentration dependant manner.