This paper presents square patch antenna loaded with slot split-ring resonators. Moreover, this paper discusses the performances of various dielectric substrates, having dielectric constants ranging from 2 to 5. Different substrate has been used to design the antenna such as Bakelite, Rogers RO 4232 and RT Duroid with dielectric constant of 4.8, 3.2 and 2.2, respectively. The resonance frequency is 2.25 GHz; these antennas are suitable for S-band and communication applications. The effect of change in substrate material on the performance of antenna is compared, in terms of reflection coefficient, bandwidth, directivity and radiation pattern.