The resonance light scattering (RLS) technique and UV-Vis absorption spectra were applied to the investigation of the interaction between atrazine and bovine serum albumin(BSA). Under acidic conditions, the formation of atrazine-BSA supermolecule by Van der Waals force and N/O--H...pi hydrogen bonds leads to a red shift of absorption band and strong RLS enhancement of atrazine. The characteristics and intensity of RLS were related to the pH, the concentration of atrazine, and temperature. Under the optimum conditions, the enhanced RLS intensities are in proportion to the concentration of BSA in the range of 0.05-100 microg x mL(-1). Based on the enhancement of the RLS, a simple and sensitive method for the determination of BSA was established. The detection limit (3sigma) is 12 ng x mL(-1). Synthesis samples were determined with satisfactory results.