A comprehensive HPLC-DAD-MS method was developed to study the chemical components of semi-bionic extract of Coptis-Evodia herb couple. The extract was isolated on a Hypersil BDS C18 column (4.6 mm x 200 mm, 5 microm) using acetonitrile-ammonium formic buffer as mobile phase by gradient elution. Detection was performed on DAD and MS equipped with an electrospray ionization (ESI) source by full scan and product full scan on positive mode. The chromatogram of Coptis-Evodia showed seventeen main peaks, eight of which were from Evodia while the others were from Coptis. By comparison of the retention time, the on-line UV spectra and MS spectra, four peaks were identified as jatrorrhizine, hydroxevodiamine, palmatine and berberine, and three peaks were deduced as epiberberine, columbamine and coptisine. In addition, berberine and palmatine were quantitatively determined. No new component was created in the semi-bionic extract of the herb couple, yet the solubilities of berberine and palmatine decreased.