In this study, the influence of Magnetohydrodynamics on free convection slip flow of an exothermic fluid in a convectively heated vertical channel is analyzed. The problem is solved analytically using perturbation series method and expression for velocity, temperature, skin friction, Nusselt Number are obtained and also the influence of some physical parameters such as Hartmann number(Ha), Biot number(Br), Navier slip parameter(γ) and Frank-Kamenetskii parameter(λ) are discussed. It is observed that both velocity fluid and skin friction decreases with increasing value of Hartmann number.