A pharmaceutical composition containing sunflower extract comprises the extract of total flavonoids from leaves, heads or stems of sunflower (Helianthus annuus L.), in which the content of total flavonoids is 50-90%. Preferably, the pharmaceutical composition comprises the extract of total terpenes and/or the extract of total organic acids. The pharmaceutical composition is used as an active ingredient in manufacture of foods, functional foods or medicaments for preventing or treating hypertension.