Spinel cobalt ferrite (CoFe 2 O 4 Abstract ) (CFO) nanoparticle have fantastic and remarkable combination of properties, principally its electrical and magnetic properties. These properties are make CoFe 2 O 4 is a good candidate in the field of electronics. In this study Brown equation, Bloch modified and Krenell’s modified equation are used to calculate magnetic parameters. The magnetic properties were related to the size, temperature and concentration of cobalt particles and the electrical properties linked to the cation distribution between tetrahedral and octahedral sites. The magnetic saturation and coercivity of cobalt ferrite depend on the particle size. As cobalt content increases magnetic saturation decreased .This was for the reason that as the cobalt content increased, the particle size reduced and this makes as magnetic saturation decreases . Magnetic saturation and coercivity also influenced by particle size. The decrease of coercivity of cobalt ferrite nano particle with increase of particle size attributed to two reasons; first the cross over from single domain to multi domain and second such an effect can arise from a combination of surface anisotropy and thermal energies. The decrease in magnetic saturation at small sizes was attributed to the effects of the relatively dead or inert surface layer that has low magnetization. A.C conductivity was derived from dielectric constant and loss tangent data. At lower frequency A.C conductivity was increased and it was independent of frequency at higher frequency. This was for the reason that as the frequency of the applied field increases, the jumping of charge carriers (Fe 3+ , Co 2+ ) also increases there by increasing the conductivity. But at higher frequencies, the jumping of charge carriers (Fe 3+ , Co2 + ) could not follow the applied field frequency and it lags behind the applied frequency resulting in a decrease in the ac conductivity values. Keywords:-coercivity, magnetic saturation, anisotropy, electrical property.