A novel microstrip fed ultra wideband antenna is proposed in this paper.The antenna was etched on a copper cladding substrate.The size of the substrate is 30 mm×35 mm×1.6 mm and the substrate material uses FR4 with relative permittivity of 4.4.The antenna parameters have been simulated and optimized by using the simulation software HFSS.The bandwidth (return loss≤-10 dB) starts from 2.6 GHz up to 11.5 GHz that means a relative bandwidth of 126% by slotting on the surface of microstrip.The results show that the designed antenna not only realizes UWB but also is simple in structure, small in size and suitable for UWB communications.