The present work entitled “study of Sn doped Ni-Zn ferrites” deals with the studies of the physical processes leading to the anomalous behavior of magnetization in Sn4+ (tin) substituted Ni-Zn ferrites. X-ray diffraction pattern is taken into account to characterize the samples. EPR spectra at room temperature and liquid nitrogen temperature were recorded to understand the nature and strength of the interaction of the spin with its environment. The study is divided into five major chapters and is aimed to visualize the effect of variation of Sn concentration in ferrites. The chapter Material and Methods tells a brief theory of Electron Paramagnetic Resonance (EPR) and the basic properties of ferrites. The ‘g’ value and Hpp value for the above ferrites with different Sn concentration is calculated from EPR spectra. The average particle size and lattice parameters are also calculated for the samples with the help of X-ray diffraction pattern. The chapter Result and Conclusion presents the important findings of the present work and their plausible explanation.