The difference UV spectra and fluorescence of Bu_2SnCl_2 and ethylene bis (o-hydroxyphenylglycine) (EHPG), a ligand used previously for mimicking Fe~(3+) binding of transferrins, was first studied in Tris-HCl buffer solution (pH7.4). Difference UV spectral studies show that the binding of Bu_2SnCl_2 to EHPG takes twelve hours and gives rise to a 1:1 complex. The binding constant for Bu_2SnCl_2-EHPG complex is estimated to be 1.65×10~3 M~(-1). Fluorescence studies also show an increase in intensity of EHPG after interaction with Bu_2SnCl_2. The difference UV spectra and fluorescence of Bu_2SnCl_2 and ethylene bis (o-hydroxyphenylglycine) (EHPG), a ligand used previously for mimicking Fe 3+ binding of transferrins, was first studied in Tris-HCl buffer solution (pH 7.4) . Difference UV spectral studies show that the binding of Bu_2SnCl_2 to EHPG takes twelve hours and gives rise to a 1: 1 complex. The binding constant for Bu_2SnCl_2-EHPG complex is estimated to be 1.65 × 10 ~ 3 M -1. Fluorescence studies also show an increase in intensity of EHPG after interaction with Bu_2SnCl_2.