High-performance submicron-scaled NiCuZn ferrites are prepared by the solid-state reaction method through using CuO as additive. In the synthesis process, a mixture of superfine powder is sintered at 900 °C for 3 h, and the obtained product is NiZn-ferrite with spinel structure. We observe that the particle size increases with raising the sintering temperature. The NiCuZn ferrite with relatively uniform size and granular shape has the best performance: its coercivity is 14 Oe (1 Oe=79.5775 A·m-1) and saturation magnetization is 48 emu/g. We also study the effects of particle size, magnetocrystalline anisotropy, and microstructure on coercivity. The method presented here is convenient and economical for producing the high-permeability ferrite powders.Project supported by the National Natural Science Foundation of China (Grant Nos. 11174132, 11474151, and U1232210), the National Key Project for Basic Research, China (Grant Nos. 2011CB922102 and 2012CB932304), the Innovation Program for Doctoral Research of Jiangsu Province, China (Grant No. CXZZ13_0035), and the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions, China.