A simple and efficient preparation of Mg/Al layered double hydroxide is reported in this letter. Fouled and waste 201 x 7 type anion-exchange resins as precursors and templates provided abundant CO32- for the Mg/Al layered double hydroxide. The products were characterized through scanning electron microscopy, X-ray diffraction, thermogravimetry/differential thermal analysis, and Fourier-transform infrared spectroscopy.