The　structural　changes　of　human　serum　albumin　(HSA)　induced　by　the　addition　of　cadmium　acetate　were　systematically　investigated　using　UV-vis　absorption,　circular　dichroism　(CD),　synchronous,　and　three-dimentional　(3D)　fluorescence　methods.　The　fluorescence　spectra　suggested　the　formation　of　cadmium　acetate-HSA　complex.　UV　absorption　result　indicated　that　the　interaction　between　cadmium　acetate　and　HSA　could　lead　to　the　alteration　of　the　protein　skeleton.　The　structural　analysis　according　to　CD　method　showed　that　the　cadmium　acetate　binding　altered　HSA　conformation　with　a　major　reduction　of　α-helix,　inducing　a　partial　protein　unfolding.　Synchronous　fluorescence　spectra　suggested　that　cadmium　acetate　was　situated　closer　to　tryptophan　residue　compared　to　tyrosine　residues,　making　tryptophan　residue　locate　in　a　more　hydrophobic　environment.　3D　fluorescence　demonstrated　that　cadmium　acetate　could　induce　the　HSA　aggregation　and　cause　a　slight　unfolding　of　the　polypeptide　backbone　of　the　protein.　©　2014　Wiley　Periodicals,　Inc.