The restriction of non renewable fossil resources, environment problems makes people to use fuel cell technology, since it is very stable, safe and compatible with environment. Solid oxide fuel cell has a high efficiency and low pollution emissivity to converting chemical energy to electrical energy, so it will used in future very widespread. The temperature of solid oxide fuel cell is very high and we can use it with other hybrid system. In this theses solid oxide fuel cell with internal reformer combined with micro gas turbine as a basic system. By electrochemical and thermodynamic model and determining of the overvoltage in different case, cell voltage obtained. The effect of temperature, pressure and mole fraction of reactant gases as a basic parameters, the effect of cell sizing, ratio of producing power in each section as a secondary parameters were considered. The first and second low of thermodynamic has utilized. By using combined cycle (SOFC/MGT) energy analysis showed 32% increasment efficiency and it reached to 83%. Exergy analysis done and it implied that largest place of destroyed exergy occur in external reformer and second low efficiency was calculated 65%.