Ultrafine zinc oxide powders with different appearances were prepared in the presence of different surfactants in system of Zn(NO₃)₂NaOH.Using a simple method in the open air,ZnO particles were directly obtained from aqueous solution under the condition of boiling and refluxing.The crystal structures,particle sizes and appearances of ZnO powders were characterized by X-ray diffraction and scanning electron microscopy respectively.The results show that the as-grown ZnO crystals are hexagonal wurtzite ZnO.Moreover,different surfactants used in the experiment have different effects on the shapes of the products.