The affinity of mono- and di-substituted benzene derivatives bearing OH, NHCO and NHSO₂ groups toward anions (Cl^-, Br^-, I^-, NO₃^-, HSO₄^-) were investigated by ¹H-NMR spectroscopy in CDCl₃. The anion affinity and the selectivity of these benzene derivatives are ruled by the following three factors: i) the strength as hydrogen bonding donor of the binding sites, ii) the hardness of an anion in HSAB theory, iii) the adaptability of the shape of the binding site and the anion.