Lanthanum aminopolycarboxylates, Na12n[La(edta)L]4n·8nNaCl·4nH2O (1: L = HPO32−; 2: L = CO32−) and K12n[La(cdta)(CO3)]4n·35nH2O (3), with square structures were obtained. Carbonate 2 possesses 3.7 Å diameter holes that can adsorb a small amount of O2 or CO2 selectively.