Two chromium ternary complexes with nitrilotriacetic acid as a primary ligand and alanine or glycine as secondary ligand were prepared in slightly acidic medium. The structure of these two complexes was characterized using elemental, thermal analysis, FTIR spectra, and the two complexes mass spectra. The spectroscopy data suggest that these two complexes were in polymeric form and have the monomeric unit H[Cr(HNTA)(Hala)(SO4)] and H[Cr(HNTA)(Gly)(SO4)] in which sulfate group act as a bidentate ligand linked between each monomeric unit for the same complex. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012