In the present paper, the interaction between ambroxol hydrochloride (ABX) and human serum albumin (HSA) was studied under simulative physiological condition by spectroscopy and molecular modeling method.Stern-Volmer curvers at different temperatures and UV-Vis absorption spectroscopy showed that ABX quenched the fluorescence of HSA mainly through dynamic quenching mode.On the basis of the thermodynamic data, the main binding force between them is hydrophobic interaction.According to the theory of Frster non-radiation energy transfer, the binding distance between the donor and the acceptor was 3.01 nm.The effect of ABX on the conformation of HSA was analyzed by the synchronous and three-dimensional fluorescence spectroscopy.Furthermore, using the molecular modeling method, the interaction between them was predicted from molecular angle: ABX might locate in the subdomain ⅢA of HSA.