Abstract: The mutual coupling between microstrip antenna elements has affected the performances of microstrip arrays, on the other hand, substrate cover or superstrate-loaded on microstrip arrays is necessary to prevent the damage of nature or man made. The effect of substrate cover should be considered when we design conformal microstrip antenna and arrays. This paper proposes an analysis and computation of mutual coupling of superstrate-loaded cylindrical-rectangular microstrip antennas fed by coaxial probe by using rigorous full-wave method. The calculation results about mutual coupling of E- and H-plane are given. The variations of the mutual coupling with curvature of cylinder, the spacing between microstrip elements and frequency are discussed. The coupling with different grounded dielectric substrate and superstrate are analyzed simultaneously.