In this study, the antioxidative effects and inhibitory effects on tyrosinase and elastase of Sorbus commixta (S. commixta) twig extracts were investigated. The aglycone fraction of S. commixta twig extract showed the prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity($FSC_{50}$, $13{mu}g/mL$). Reactive oxygen species (ROS) scavenging activities of S. commixta twig extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated by the luminol-dependent chemiluminescence assay. The 50 % ethanol extract among extracts showed the most prominent ROS scavenging activity ($OSC_{50}$, $0.189{mu}g/mL$). The cellular protective effects of extract/fractions of S. commixta twig on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The 50 % ethanol extract and ethyl acetate fraction showed the cellular protective effects against ROS in a concentration dependent manner ($5{sim}50{mu}g/mL$). The inhibitory effect of S. commixta twig extract on tyrosinase was investigated to assess the whitening efficacy. The ethyl acetate ($IC_{50}$, $113.2{mu}g/mL$) and aglycone fraction($IC_{50}$, $105.3{mu}g/mL$) on tyrosinase showed more remarkable inhibitory effect than arbutin($IC_{50}$, $226.88{mu}g/mL$), known as the whitening agent. The inhibitory effect of aglycone fraction ($IC_{50}$, $6.9{mu}g/mL$) on elastase was simillar to quercetin($IC_{50}$, $6.1{mu}g/mL$), flavonoid known as reference compound. These results indicate that extract/fractions of S. commixta twig can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. S. commixta twig extracts can be applicable to new functional cosmetics for anti-aging products.