For determination of the stability of In3+ complexes with diethylenetriaminepentaacetic acid (DTPA) and newly synthesized chelates-derivatives of 4-amino-2-hydroxybutyric acid in aqueous solutions of pH 1.0–7.5, at room temperature, the time differential perturbed angular – correlation method was used. Data obtained show that only one of the new ligands forms as strong a complex as DTPA and can be used in water at pH7.