Pteris multifida Poiret (Pteridaceae), also known as Fong‐Wei‐Cao, is the most commonly used material in herb beverages in Taiwan and also used as one of the vegetable resources in Main China. The aqueous extract of P. multifida Poiret (AEPM) was prepared and its antioxidant and free radical‐scavenging activities were studied. AEPM showed high antioxidant activities by conjugated diene method. At 20 mg/mL, AEPM exhibited high scavenging effects on α‐diphenyl‐β‐picrylhydrazyl, hydroxyl, ferrous radical (82.5, 80.1 and 85.4, respectively) and reducing power (Abs, 700 nm = 1.03). AEPM has various antioxidant activities that may be due to the different naturally occurring antioxidant components. PRACTICAL APPLICATIONS Consumers need high‐quality herb‐beverage products and to understand their potential functions. Our results indicated that the qualities of aqueous extract of P. multifida Poiret possess antioxidant and free radical‐scavenging activities and this evidence could be regard as the important scientific basis.