The effect of additives on the coprecipitation preparation processs was studied in this paper. The pure, nanometer Mn-Zn ferrite crystallites with good magnetic property and a narrow grain size distribution were obtained by adding additives. And the influence of additives on the XRD patterns, magnetic properties and Curie temperature of Mn-Zn ferrite was investigated. The results of the research indicate that additives can make the crystals grow more perfectly and bigger, and improve the magnetic properties of the ferrite, and decrease Curie temperature. （From : No.1, 2006 Glass & Enamel）