Using ab-initio calculation based on the Korringa-Kohn-Rostoker Coherent Potential Approximation (KKR-CPA) method in connection with the local density approximation without and within self-interaction-corrected (LDA and LDA-SIC), we represent a theoretical study of the SnO2 doped system with transition metals (TM) which are Iron (Fe) and Cobalt (Co). In this system, the stability of the ferromagnetic state compared with the spin-glass state is investigated by comparing their total energies. The Ferromagnetic and half metallic behaviors was observed and conformed with the local-moment-disordered (LMD) state energy for LDA (local density approximation) and LDA-SIC (local density approximation-self-interaction correction) approximation in [Sn0.95TM0.05(Fe or Co)]O2 . Based on mean field method, the Curie temperature is estimated. To explain the origin of magnetic behavior, we give information about total and atom projected density of states functions of Fe and Co elements and we propose a model which describes magnetic interaction in [Sn0.95TM0.05(Fe or Co)]O2
