The title complexes [Al（Hcah）（H2O）2]·2H2O （A） and [Bi（Hcah）（H2O）]n （B）, where H4cah = 2-[N,N-bis（carboxymethyl）aminomethyl] hydroquinone, have been synthesized and characterized using X-ray single-crystal structure determination, IR and elemental analysis. Both complexes crystallize in the monoclinic system, space group P21/c with a = 7.8660（16）, b = 10.096（2）, c = 19.053（4） and β = 93.50（3）° for A; and those for B： a = 9.2348（18）, b = 7.9061（16）, c = 17.141（3） and β = 102.64（3）°. In addition, further investigation revealed that the central Al（III） ion in the mononuclear complex A is in a distorted octahedral coordination geometry, while structural analysis reveals that the Bi（III） ion is in a distorted pentagonal bipyramid, forming a 2-D polymeric complex B, and the coordination network is a 2D 4.82 net. The TG analyses of A indicate two steps of water loss.
