This study aimed at making an investigation on the effect of the magnetic field on second law analysis for magnetohydrodynamic (MHD) permeable channel flow with convective cooling. Specifically, the study intended to develop a flow model for a case of nanofluid in a channel, determining the effect of different parameters on velocity and temperature of nanofluid and to determine the effect of the magnetic field on the channel flow of nanofluid.In this study, the appropriate mathematical model for the problem was derived from the laws of conservation, momentum and energy balance where both first and second laws of thermodynamics are utilized to analyze the model problem. Using the discretization finite difference method together with the Runge-Kutta Fehlberg integration scheme, the governing partial differential equations are solved numerically and implemented on the Computer using Matlab software. The findings showed that the alumina water nanofluid tended to flow quicker than copper water nanofluid and the velocity profile increased with Hartmann number but decreased with the quantity of nanoparticle volume fraction and magnetic field.