Abstract: OBJECTIVE To determine the active fractions of Callicarpa nudiflora on inhibitory of nitric oxide production, and to establish a method for identification of the main compositions of Callicarpa nudiflora by HPLC-DAD-ESI-MS technology. METHODS The inhibitory activity of nitric oxide production was carried out using lipopolysaccharide (LPS) to induce macrophage RAW264.7. The main compositions were determined by HPLC-DAD-ESI-MS technology. RESULTS The petroleum ether fraction and ethyl acetate fraction of Callicarpa nudiflora could inhibit the production of nitric oxide in lipopolysaccharide induced RAW264.7 cells (IC₅₀<25 μg·mL^-1). Flavonoids and flavonoid glycosides were the main constituents of ethyl acetate fraction, and the main constituents of petroleum ether fraction were flavonoids and diterpenoids. CONCLUSION The research provides a reference for the upgrading of products and the quality control of Callicarpa nudiflora.