Prunus padus bark extract was tested for use as a natural cosmetic ingredient. P. padus bark extract was obtained by hot water extraction and succeeding maturing processes. Total polyphenol and flavonoid concentrations were measured, and safety test (cell toxicity test), efficacy tests (antioxidation, antiwrinkle, whitening), and temperature stability tests were conducted in experiments. Total polyphenol and flavonoid concentrations were 714.7±0.5 mg/g and 72.1±2.2mg/g, respectively. Compared with other natural antioxidants, polyphenol concentration in P. padus bark extract was extremely high. P. padus bark extract showed lower cell toxicity in 100-500 μg/ml concentration by MTT assay. P. padus bark extract indicated 71% DPPH free radical scavenging activity (antioxidation), 36% elastase inhibition (antiwrinkle), and 38% tyrosinase inhibition (whitening) at 350 μg/ml, respectively. W/O/W lotion formulation containing 1% P. padus extract was prepared and stability tests were done to see variations in cosmetic properties. Viscosity, pH, particle size, and appearance of lotion containing 1% P. padus extract maintained stable condition for 28 days. Particle size of lotions showed homogeneous 362-426 nm ranges during stability tests. From this study, P. padus bark extract displayed strong possibility as a natural antioxidative cosmetic agent.