AIM: To study the chemical constituents of Longdan Xiegan Decoction, one of the most famous Traditional Chinese Medicine prescriptions. METHODS: Silica gel, C18 reversed phase silica gel, Sephadex LH-20 column chromatography were used. The structures of isolated compounds were elucidated by various physiochemical properties and spectral data. RESULTS: Five com-pounds were obtained and identified as 2',4' -dihydroxydihydrochalcone-3'-C-β-glucopyranosyl-6'-O-β-D-glucopyranoside (1), isoliquiritigenin (2), echinatin (3), licochalcone B (4), and isoliquiritin (5). CONCLUSION: Compound 1 is new and compounds 2-5 were isolated from Longdan Xiegan Decoction for the first time.