A composite radome is a durable structure to protect telecommunication radar antennas against mechanical and environmental factors. Due to its placement in front of the antenna and the possibility of affecting the received and transmitted waves, in addition to the mechanical properties, the electromagnetic properties of this structure are very important. In this study, the mechanical properties (tensile strength in the direction of fibers) and the electromagnetic properties (DIELECTRIC CONSTANT at X-band frequency) for a GFRP composite radome has been studied and optimized. For this purpose, two types of glass fibers E and D series, and two types of epoxy resin and polyester resin have been used. In addition, three common methods of composite fabrication including hand layup, vacuum bag, and vacuum infusion have been used. Also, by using the Taguchi test design method and signal-to-noise analysis, the optimal composition was obtained for each of the properties, which for tensile strength of the combination of E series glass fibers and epoxy resin and vacuum bag fabrication method, the highest tensile strength was 320. 9 MPa and for the DIELECTRIC CONSTANT of D series glass fibers and epoxy resin and vacuum bag fabrication method with the lowest value of 2. 85 were determined. After determining the optimal composition for each of the properties, the optimum state was investigated by considering all the mechanical and electromagnetic properties factors together by using the multi-response optimization method (gray relation). Finally, a combination of D-series glass fibers, epoxy resin, and vacuum bag fabrication method was proposed.