A single feed compact rectangular micro strip antenna for triple band application is presented in this paper. A C-shaped slot is etched in the patch of the antenna and T-shaped, I-shaped patch are introduced in the ground of the antenna. The antenna operates in three resonant frequencies at 3.8GHz (WiMAX), 5.8GHz (WiFi) and 9.3GHz (X-band). The design is analyzed using HFSS which is based on Finite Element Method (FEM). The dimension of the antenna is 18 mm × 25 mm × 1mm3 and the dielectric substrate with er = 4.4. The simple configuration and low profile nature of the proposed antenna is suitable for Wireless communication system. The antenna has radiation efficiency of 92%.