Antenna is a device which radiates electromagnetic energy intofree space in all directions single antenna characteristics like high beam width, low gain and low bandwidth are notsufficient in radar communication system for beam steering array antennas are designed for improving the parameters of beam width, gain and bandwidth. for this array of Horn antenna is designed. In the conventional arrays side lobe level - 13.5 dB is the obstacle to find the object in the radar system since mainbeam to first side lobe level is -13.5 dB. In the first side lobe level the most of the power is diverted from main beam, toovercome this and reduce the side lobe level is the array system. Standard amplitude distribution is used to reduce side lobelevel. In this work triangular amplitude distribution is used to reduce the side lobe level up to -26.8dB. The standard Hornantenna is used in this work to produce narrow beams and high gain. By neglecting inter element interference the desiredHorn arrays for N=10, 20, 40, 60 are designed. By adopting standard amplitude distribution to these arrays side lobe levelarealso reduced andarecompared withtheisotropicarrays.Theresultscomeupwith goodagreement.