The aim of this work is to design and analysis the performance of a metamaterial (MTM) based microstrip patch antenna (MP A) by introducing three dual isosceles triangular slots on the metallic patch. At First, a conventional microstrip patch antenna is designed using Isola FR-408 (loss free) substrate material having dielectric constant of 3.75. Then the slotted microstrip patch antenna has been designed and verified as left handed metamaterial (LHM) with the help of Nicolson Ross Weir (NRW) method. All the simulations have been accomplished by CST microwave studio 2011. The bandwidth of the proposed MTM antenna is enhanced by 464.93% compared to our designed conventional MPA (77 MHz for conventional MPA and 435 MHz for metamaterial MPA) and the return loss is reduced from -11.89 dB to -55.34 dB and directivity is increased from 6.713 dB to 7.187 dB. The voltage standing wave ratio (VSWR) of the proposed metamaterial antenna is of 1.0034 which is very close to unity.