Abstract: The effect of spectral properties and conformation of bovine serum album (BSA) by anthocyanin (ACN) was studied under simulated physiological conditions. Fluorescence spectroscopy was used to determine the quenching mode, number of binding sites, binding force type and non - radiative energy transfer between ACN and BSA. And BSA conformational changes were characterized by means of UV-Vis absorption spectrometry, circular dichroism spectroscopy and Fourier infrared absorption spectroscopy.The results showed that BSA endogenous fluorescence was quenched regularly with ACN, and the quenching mechanism was static quenching of ACN-BSA complex and non - radiative energy transfer. The quenching process was spontaneous by hydrophobic force, and the binding-site number was about 1. Furthermore, the binding sites were located in site 1 in the subdomain of BSA, and the α-helix of BSA was reduced by 3.1% in the presence of ACN.The interaction of ACN and BSA is strong, which causes a conformational change of BSA.