The two dimensional steady, combined forced and natural convection in vertical channel isinvestigated for laminar regime. To simulate the Trombe wall channel geometry properly, horizontalinlet and exit segments have been added to the vertical channel. The vertical walls of the channel aremaintained at constant but different temperature while horizontal walls are insulated. A finitedifference method using up-wind differencing for the nonlinear convective terms, and centraldifferencing for the second order derivatives, is employed to solve the governing differentialequations for the mass, momentum, and energy balances. The solution is obtained for streamfunction, vorticity and temperature as dependent variables by iterative technique known as successivesubstitution with overrelaxation. The flow and temperature patterns in the channel are obtained forReynolds numbers and Grashof number ranging from 25 to 100 and (100 to 1,000,00,) respectively.A computer program ( Fortran 90 ) is built to calculate the fraction factor and the totalaverage Nusselt number (Nu) also the average heat transfer Q in steady state and for Aspect ratio Ar(10) and Grashof number GR (10 2 − 10 5 ), the fluid Prandtl number is fixed at (Pr=0.733) andReynolds number Re (25-100).The results show reasonable representation to the relation between Nusselt number and frictionfactor with other parameters (Ar, GR and Re). Nu is increased with increasing Re and GR but itdecreases with Ar increase and (Q) is increased with increasing Re ,GR and Ar. At the same time, theproduct friction factor(fRe) increased with (GR) and (Ar)increased and (Re )decrease.Comparison of the result with the previous work shows a good agreement