ZnS nanoparticles was synthesized using zinc acetate and sodium sulfide as starting materials in water solution.The morphology and crystal phase of nano-ZnS were characterized by transmission electron microscopy（TEM） and powder X-ray diffraction（XRD）.The interaction of nanoparticles and bovine serum albumin（BSA） was investigated by fluorescence spectroscopy in pH 7.0 Tris-HCl buffer.The result showed that the interaction between BSA and ZnS nanoparticles could resulted in the endogenous fluorescence quenching of BSA,which belonged to a static quenching mechanism.The quenching rate constant was 1.88×1014 L?mol-1?s-1,the binding constant（Ka） and binding site（n） were 1.73×105 L?mol-1 and 0.83,respectively.