In this paper, the authors present the design of compact monopole antenna with very wide bandwidth for Wi-MAX application. The proposed antenna radiates at a bandwidth which meet the requirements of Wi-MAX standards. It uses the easily available low cost FR4 substrate, which makes the antenna cost effective. The antenna structure consist a straight I shaped slit at the center of radiating edge to produce notched band in 3.3 - 3.7 GHz for the WiMAX system which gives very wide bandwidth performance. The proposed Y shaped structure is very compact compared to conventional microstrip geometries like rectangular patch antenna.