Two Element Microstrip Antenna Array with Defected Ground Structure. This paper presents a two elementmicrostrip antenna array using trapezium shape defected ground structure (DGS). The DGS is inserted in the groundplane between two elements of antenna array. Insertion of the DGS is intended to suppress the mutual coupling effectproduced by antenna array. Simulation and measurement results were taken and compared between antenna array withand without DGS. Measurement results show that the antenna with DGS compared to antenna without DGS cansuppress mutual coupling effect to 7.9 dB, improve the return loss to 33.29% from -30.188 dB to -40.24 dB and axialratio bandwidth enhancement to 10 MHz. This bandwidth enhancement is achieved from frequency 2.63 GHz – 2.67GHz for antenna without DGS and from frequency 2.63 GHz – 2.68 GHz for antenna with DGS. In addition, the DGSantenna also improved the antenna gain to 0.6 dB. The results show that the implementation of the trapezium DGS canimprove the radiation properties of the antenna without DGS.