The effect of chemical reaction,radiation absorption and thermo-diffusion on MHD convective heat and mass transfer flow in Channels / Ducts with heat sources gives the study of heat generation or absorption effects in moving fluids, such as fluids undergoing exothermic or endothermic chemical reaction. Due to the fast growth of electronic technology, effective cooling of electronic has become warranted and cooling of electronic equipment ranges from individual transistors to main frame computers and from energy suppliers to telephone switch boards and thermal diffusion effect has been utilized for isotopes separation in the mixture between gases with very light molecular weight (hydrogen and helium) and medium molecular weight.