Abstract Ammoniapropionicdiacetic acid (APDA), which belongs to a group of chelating agents similar to that of ammoniatriacetic acid, was prepared. The newly-prepared complexes containing this chelating agent were as follows: [Cr(OH)(apdaH)(H2O)2] (red purple) (I), NH4[Cr(OH)(apda)(H2O)]·2H2O (purple) (II), (NH4)3[Cr(apda)2]·2H2O (pink) (III), (Cr(apda)-(bipy)]·3H2O (brown) (IV), [Cr(apda)(o-phen)]·3H2O (brown) (V), and [Cr(apda)(py)2](pink) (VI), where apda, bipy, o-phen, and py are the abbreviations of the ammoniapropionate-diacetate ion, o-phenanthroline, 2,2′-bipyridyl, and pyridine respectively. On the basis of the chemical and thermal analyses, and on the basis of the measurements of the visible, UV, reflection and IR spectra and molar conductivities, it was concluded that the ammoniapropionatediacetate acts either as a terdentate or a quadridentate ligand in these complexes. Unlike the ATA complex, no complexes in which the nitrogen dose not coordinate with chromium could be prepared in the case of APDA. The values of the effective magnetic moments for these APDA complexes were nearly equal to the spin-only values of tervalent chromium. Further comparisons of the properties of the APDA complexes with those of the ATA complexes were also made.