The reaction of iron (Ⅲ ) anions ,FeCl3 and Fe2 (SO4 )3 with tris (hydroxymethyl) aminomethane (Tris) in a 1:2 molar ratio affords the new coordination compounds NH4 [Fe2 (Tris)2 (H2 O)4 (SO4 )] (Ⅰ ) and NH4 [Fe(Tris)2 (H2 O)2 ] (Ⅱ) .These compounds were characterized by elemental analysis ,and their mo-lecular structures were determined by spectroscopic methods (infrared and electronic spectra) ,magnetic sus-ceptibility ,and molar conductivity measurements ,and further corroborated by thermo gravimetric analysis and its differential (TGA/DrTGA) .According to the experimental data ,the complexes can be characterized in the solid state as mono-and binuclear ,with a distorted octahedral stereochemistry .The distorted octahedral stere-ochemistry adopted by the complexes was confirmed by the magnetic susceptibility measurement of NH4 [Fe2 (Tris)2 (H2 O)4 (SO4 )] ,which consists of a six-coordinate iron atoms in a distorted octahedral environment constructed from four O atoms (two Tris molecules) ,two O atoms from the loosely associated SO4 coordinated ligand ,and O ,N of second Tris molecule with occupying by four oxygen atoms of coordinated water mole-cules.Regarding,NH4[Fe(Tris)2(H2O)2]complexthemonoironatomissurroundedbysixoxygenatomsas four by two Tris molecules and two coordinated water molecules in axial form .Antibacterial and anticancer ac-tivities of the complexes were studied and the complexes were screened against bacteria ,colorectal adenocarci-noma (Caco-2) and breast cancer (Mcf-7) cell lines .