During this work, pure and doped SnO2 thin films with different concentration of Co (3 and 7)% wt. have been prepared by chemical spray pyrolysis method on glass substrates preheated to 500°C. The structure of these films has been examined using X-Ray diffraction analysis and the results show that the pure films were amorphous and converted to polycrystalline after doping with Co with strong crystalline orientation (110) and it is affected slightly with increasing of Co content. The electrical properties of these films were studied with different concentration of Co. The d.c. conductivity for all deposited films was decreased with increasing Co contents while the resistivity increased.Also, it was found that there is towregion of activation energy and the electrical activation energies increase with increasing the concentration of Co. Hallmeasurements showed that all the films are n-type and carrier concentration decreases with the increasing of Co concentration. Furthermore, we observe that the mobility increases with increasing of Co content while drift velocity is increased.