In this thesis the effect of EHD on natural convection heat transfer enhancement from an inclined uniformly heated plateis investigated experimentally.The electric fieldis applied on the metallic heated plate by a wire electrode. In such condition mentioned above, applying an electric field induces a secondary motion in air,names “Corona Wind” and this wind is responsible of increasing heat transfer coefficient.The effect of eight parameters on the phenomena was investigated. The angle of inclined heated plate, the amount of heat flux , the diameter of the wire electrode, the distance between the wire and the plate, the configuration ofthe wire electrode, the amount of applied electric field and the electric current which induced after applying the electric field, are the eight parameters.First the result of the experiments is compared with the natural convection formulas results for heated plate. After ensuring ofthe measurements the amount of enhancing heat transfer coefficient which is introduced by E r -the ratio of heat transfer coefficient after applying electric field to one before it- is investigated. Results show that increasing applied voltage and electric current will increase heat transfer coefficient but little by little the slope of the increment decreases. Also, increasing the distance of the wire electrode from the plate – in constant applied voltage or current – will decrease heat transfer but this reduction is much lower for the case that we have constant current. It can be found from the results that the double path configuration for the wire electrode will uniform the effect of electric field on the plate and consumes lower amount of energy for the case that we have equal E r . Results show that for a given distance and configuration of the wire electrode, the amount of heat transfer coefficient of each point of the plate is independent of the diameter of the wire electrode, and is only a function of the electric current, Although, the bigger diameter of the wire consumes more electric power in the case that we have constant electric current. It can be seen that increasing the angle of the plate with respect to the horizon , will increase E r , and this increment is much higher for the angles that approaches to 180?.Finally, one can say EHD is an effective method in enhancing heat transfer such that the amount of E r in the case that the distance of wire electrode to the plate was 5 centimeters and the applied voltage was 17.5 kV and the angle of the plate was 180?, was 4.5 and it is completely possible to increase this amount by increasing applied voltage and decreasing the distance of the wire electrode to the plate. Key Words Electrohydrodynamic, heat enhancement, heated plate, inclined plate.