Twelve compounds have been isolated for the first time from Oxalis corniculata namely, ß-sitosterol (1), betulin (2), 4-hydroxybenzoic acid (3), ethyl gallate (4), 5-hydroxy-7,8-dimethoxyflavone (5), 5-hydroxy-3,4,6,7,8-pentamethoxyflavone (6), 7,5'-dimethoxy-3,5,2'-trihydroxyflavone (7), 5-hydroxy-3,6,7,4'-tetramethoxyflavone (8), 4',5-hydroxy-3,6,7-trimethoxyflavone (9), 5-hydroxy-3,6,7,4´-tetramethoxyflavone (10),apigenin 7-O-ß-D-glucoside (11) and 3,3',5,7-trihydroxy-4'-methoxyflavone 7-O-ß-D-glucopyranoside (12), respectively. Their structures have been elucidated by EI-MS, HR-EI-MS, HR-FAB-MS,1H-NMR and 13C-NMR spectroscopic data. Compounds 5 – 12 showed moderate antioxidant activity.