Interaction of bovine serum albumin(BSA) with fluorescent whitening agent(FWA) CBSX, BBU and VBL were studied by fluorescence spectrometry. The quenching mechanism of intrinsic fluorescence of BSA with FWAs were studied by Sternvolmer curve, LineweaverBurk curve and double reciprocal curve. The experimental results show that static quenching and fluorescence resonance energy transfer quenching are the main factors of the quenching mechanism of intrinsic fluorescence. The quenching constants and diffusion constants between BSA and FWAs(283 K) were measured, and all of the numbers of binding sites are 1. Based on the theory of Frster energy transfer spectroscopy, the binding distance r and the energy transfer efficiency between BSA and FWAs were obtained. The thermodynamic parameters of binding reactions were determined by the binding constants in 283K and 298K. All of the reaction enthalpies and the entropy were decreased. According to these, the interaction between BSA and FWAs were driven mainly by electrostatic force.