In order to screen the active constituents of Vaccinium vitis-idaea L., the compounds absorbed into the rat blood after oral administration of ethanol extract of the stems and leaves of V. vitis-idaea (EEV) have been analyzed. Two compounds were detected in the plasma and identified as arbutin and fraxin, which are originally existed in the crude drug. Furthermore, the pharmacological effects of the two compounds involving EEV for curing acute and chronic respiratory tract infection were tested. The results showed that both arbutin and fraxin have the anti-inflammatory, anti-coughing and phlegm-removing effects. Therefore, it was ascertained that the arbutin and fraxin would be the main active constituents of V. vitis-idaea L.