Abstract: Fluorophotometric study on the interation of bovine serum albumin (BSA) with amaranth (AT) in the presence of Cu(Ⅱ), Pb(Ⅱ) and Ni(Ⅱ) was made in a B-R buffer medium of pH 7.43 with λex and λem at 280 nm and 350 nm respectively. It was found that: ① due to binding with AT, quenching of intrinsic fluorescence of BSA was observed, and magnitude of the fluorescence quenching increased with increase of concentration of AT; ② upon addition of each of the 3 cations, fluorescence quenching of the reaction system of BSA-AT was enhanced at various extents; ③ each of the 3 cation take competition with AT to react with BSA to form mainly groud-state coordination complex of non-emission fluorescence, attributing to static quenching process, which enhanced the fluorescence quenching without changing the type of reaction. Non-radiative energy transfer happened to take place simultaneously with the quenching reaction, and ④ binding force of Pb(Ⅱ) with BSA hehaved to be stronger than the other 2 cations.