Abstract: The influence of zinc solution concentration and evaporation temperature on the particle size of the precursor was investigated through the preparation of activated zinc oxide precursor by using the method of ammonia volatilization, which was prepared under the conventional heating assisted by microwave -ultrasound with ammonia and zinc solution got from NH₃-NH₄HCO₃-H₂O system as raw material. The characterization of precursor showed the particle size and shape of the production prepared through microwave -ultrasound method were more controllable. SEM, X -ray diffraction and purity analysis were carried out on activated zinc oxide powder. The result showed that the addition of microwave and ultrasound contributed to obtaining uniformly distributed active zinc oxide products with average diameter of 2.3μm, and product purity over 98%.