The present study describes the total phenolic and flavonoids content and in vitro antioxidant and antibacterial activity of ethyl acetate and n-butanolic extracts from Aster squamatus growing in Algeria. Total phenolic and total flavonoids content were evaluated according to the Folin-Ciocalteu procedure, and a colorimetric method. The total phenolic amount of the two extracts was 8.86±1.31 and 19.82±1,61 mgAG/mg E respectively, whereas the flavonoids were 47.11±2.82 and 58.53±5.10 mg Q / mg E respectively. Antioxidant activity was analyzed using DPPH assay and recorded at 10-1M to be 94.55% and 87.71% for the two extracts (n-BuOH ), (EtOAc) respectively using ascorbic acid as a control test. Furthermore the antibacterial activity of the two extracts were evaluated by disc diffusion method and tested against six human pathogenic bacterial strains: The butanolic extracts showed a good antibacterial activity against klebseilla pneumoniae ATCC 700603, Staphylococcus aureus ATCC 25923, at a concentration of 0.5 mg/ml.
