Ni-Cu-Zn ferrite (NCZF) /BaTiO3 (BT) composites with different mass ratios of BT/NCZF (x) were prepared at 900°C with suitable fluxing agents. The sintered samples were then annealed in oxygen to reduce the amount of Fe2+ ions. Influence of annealing on electromagnetic properties and frequency characteristics of the samples has been investigated. The Snoek product can be somewhat improved by annealing in samples with x=10wt%, 20wt%, and 30wt%. The dielectric properties can be obviously improved in samples with x=10wt% and 30wt% after annealing in O2.