The berberine and bromophenol blue's fluorescence spectra interactions were discussed,bromophenol blue made berberine fluorescence quenching occurs,the quenching intensity with berberine concentration changed varies linearly correlation coefficient of 0. 9998,linear range of 0. 207 ~ 26 μg·m L-1,a detection limit of 0. 062 μg·m L-1,used in serum and determination of compound berberine berberine results satisfactory. A new method for the determination of berberine was proposed.