A supercritical carbon dioxide drying technique was developed to prepare nanometer particulate materials. The technique consists of preparation of an aqueous gel, filtering, washing, replacement of the water in the gel with a mixture solvent of n-butanol and ligroin and supercritical carbon dioxide drying. The product was characterized with TEM, XRD and X-ray small-angle scattering. The results indicated that an amorphous aerogel of the beryllium berate was obtained with this technique. The diameter of the product particles was about 7 nm. Isopropyl alcohol supercritical drying was also used to prepare aerogel beryllium berate, where recrystallization took place due to the high critical temperature of isopropanol.