The polycrystalline ferrites Mn-Zn-Ca have been prepared using by conventional ceramic technique, sintered at 1200°C for 4 hours. In this project, I have studied the microstructure, magnetic and electrical properties of Mn-Zn ferrites with and without additives. Investigations have been carried out by the measurements of density, microstructure, Curie temperature, permeability, loss factor, Q-factor, resistivity and dielectric constant of the samples.Curie temperature of the samples have been found to be increase with Mn addition and decreased with Ca-addition. Initial permeability increases with Mn-content and it has been also observed that with the addition of Ca the permeability of the Mn-Zn ferrites have been found to be decreased compared to the undoped samples. The loss factor increases with the increase in temperature and decreases with additives. It has been noticed that the loss factor decreases with increase in frequency.The Q-factor decreases with temperature and increases with the increase in frequency. The frequency characteristic of the dielectric constant decreases with the increase in frequency.