Micromechanical analysis is performed on the macroscopic thermal conductivity of a composite material with various misoriented elliptic reinforcements by using the equivalent inclusion method. The disturbance of heat flux occured in the material due to the reinforcement is estimated in its local-coodinate along the semi-axies of reinfocemant. By transforming the disturbance of heart flux into the global coodinate along the applied heat flux and by adopting the Mori-Tanaka theorem to the model, the volumetric average of the disturbance of heat flux can be estimated successfully. As a result, the macroscopic thermal conductivity of the composite can be expressed as a fuction of the direction cosine matrix of the orientaion of reinforcement.
