The spinel nanocrystalline Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite was prepared by polyacrylamide gel method. Influences of Nd3+ ions substitution on the microstructural and electromagnetic properties for the Co0.5Zn0.5Fe2O4 ferrites had been systematically investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and wave-guide method. The results showed that the Nd3+ ions can replace Fe3+ ions and adjust lattice parameters. The average size of the Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Nd0.05Fe1.95O4 particles were identified to be about 50nm and 60nm by TEM, respectively. The complex permittivity (=ε′-jε″) and complex permeability (=μ′-jμ″) for the composites had been measured in the frequency range of 8.2-12.4GHz. The results showed that the Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Nd0.05Fe1.95O4 ferrites had both dielectric loss and magnetic loss. The dielectric loss tangent (tgδε) and magnetic loss tangent (tgδm) for the Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite were obviously higher than those of the Co0.5Zn0.5Fe2O4. The maximal value of tgδε and tgδm for the Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite was around 0.30 at 12.4GHz and 0.16 at 10.8GHz, respectively.