The effects of Fe3+ or Fe2+ ions on the interaction of CS-Fe3O4@ZnS∶Mn/ZnS Magnetic-Fluorescent Nanoparticles(MFNPs) with Bovine Serum Albumin(BSA) have been studied using UV-visible and fluorescence spectroscopy. It was found that both the fluorescence intensity of CS-Fe3O4@ZnS∶Mn/ZnS MFNPs and BSA became weakened when Fe3+ or Fe2+ concentrations reached their physiological levels. Meanwhile, the interaction of CS-Fe3O4@ZnS∶Mn/ZnS MFNPs with BSA in the presence of Fe3+ or Fe2+ enhanced. There is synergic effect of CS-Fe3O4@ZnS∶Mn/ZnS MFNPs and Fe3+ or Fe2+ on the damage of BSA. These results are important for understanding the influence of different biological environments on interaction between MFNPs and proteins.