A bandwidth enhancement CPW-fed ultra-wideband antenna with sub-band rejection filter is presented for 2.4GHz and UWB applications. The bandwidth is broadened by embedding L-shaped slots on the CPW ground and the sub-band rejection function is achieved by etching a rectangle slot on the CPW ground. The notched band can be controlled by adjusting the length of the rectangle slot as a filter and two L-shaped slots. Experimental and numerical result shows that the proposed antenna has an impedance bandwidth range from 2.38GHz to 11.0GHz for voltage standing-wave ratio less than 2, expect the notch band frequency 4.4GHz-6GHz.