We report here from the Algerian variety of C. incana, 14 known flavonoids of which five are described for the first time in the genus Centaurea. The five new compounds are: 7,3',4',5'-tetramethyltricetin 1, 7,3',5'-trimethyltricetin 2, 3,5'-dimethyl myricetin 7-O-glucoside 3, 2"-O-glucosyl-6-C-glucosylapigenin 4, 3'-methyl myricetin 7-O-glucoside 5. The other characterized flavonoids are: 6-methoxyapigenin 6, 6-methoxyluteolin 7, 6-methoxykaempferol 8, 6 methoxyquemetin 9, apigenin-7-methylgalacturonide 10, hispidulin 7-O-glucoside 11, 6-methoxyquercetin 7-O-glucoside 12, rutin 13, 6,8-di-C-glucosylapigenin 14. The dried aerial parts of C. incana (1 kg) were successively extracted with 70% MeOH, ethylacetate and n-butanol. The concentrated extract was chromatographed on polyamide, with a gradient of MeOH in toluene. Fractions were purified by paper chromatography (Whatmann 3 MM) first with BAW (n-BuOH-HOAc-H2O, 4:1:5, upper phase) then 15% HOAc. All compounds were purified with Sephadex LH-20 prior to UV, MS and H NMR spectral analysis, colour reaction procedure, hydrolysis of the glucosides (HCl 0.1 N 2 h) and comparison with authentic samples (Mabry et al., 1970).