Layered double hydroxides (LDHs) with different kinds of metals in the brucite layer were prepared and their anion exchange properties were studied batchwise. A nitrate ion-sieve property was observed for LDHs depending on the basal spacing of the brucite layer. The distribution coefficient of nitrate ion was a maximum on the Ni-Fe type LDHs having a basal spacing of 0.81 nm.