Single-crystalline nanoplates of magnesium oxide were successfully synthesized through a calcinations route from the newly produced Mg（OH）2 precursors, which were directly prepared from the commercial bulk magnesium powders under a hydrothermal process in the absence of any additions. Scanning electron microscope （SEM） analysis indicated that the nanoplates were 2-6 μm in average width and about 80 nm in thickness. Transmission electron microscopy （TEM） images revealed that there was large quantity of nanopores with diameters ranging from 5 to 40 nm distributed in these nanoplates. The room-temperature photoluminescence （PL） spectrum of the nanoplates illustrated a strong blue emission band at 416 nm and a weak green emission band at 559 nm. Brunauer-Emmett-Teller （BET） analysis exhibited a feature of high surface of 127.21 m^2/g for the products. The fabrication mechanism of the product was also discussed.
