Objective To study the chemical principles of Huoxiangzhengqi Solution.Method To use the method of HPLC-electrospray ionization-mass spectrometry(ESI-MS) to analyse the chemical principles of Huoxiangzhengqi Solution after the sample treated with macroporous resin.Result After HPLC-ESI-MS analysis according to mass-to-charge ratio(m/z) of molecule ionic peak and featured fragments,there were 9 chemical principles determined as follows: liquiritin,hesperidinl,oxypeucedaninhydrate,xanthotoxin,glycyrrhizin,sin...