The core-shell of nanoferrites showed quite different properties rather than the nanoferrites counterpart. The nanocomposites of NiFe2O4@MgFe2O4 ([email protected]) and ZnFe2O4@MgFe2O4 ([email protected]) are chemically stable and showed very good dielectric and magnetic properties. In this investigation, the temperature-dependent dielectric constant, dielectric loss, and ac-electrical conductivity were measured up to 650 K under different alternating electric field frequencies from 100 Hz to 8 MHz. The obtained data revealed that the mutual effect between the core and the shell samples increases the space charge polarization. Also, the samples showed the semiconducting-metallic behavior which varies between SP, CBH, and QMT models according to the temperatures and the frequencies. Furthermore, the magnetization M(T) was studied of all samples using the Faraday balance method in the temperature range 300-500K. The experimental results of M(T) exhibit good magnetic properties of the core-shell samples, particularly the sample [email protected] The novelty in this work is an unexpected behavior of [email protected] which possesses magnetization higher than the pure ferrite phase (MgFe2O4), and Curie temperature (TCm) higher than the room temperature. So, the sample [email protected] is a ferrimagnetic substance. Besides, the effective magnetic moment (mEff) and the Curie-Weiss constant (q) for all samples were obtained from the magnetic susceptibility c(T) protocols.