Abstract: A novel polarization reconfigurable antenna, based on the complementary opening reconance loop structure,is proposed in this paper. Different with the traditional 180°symmetric open resonant ring, it is with 90°angle of opening structure. By controlling the opening states, the asymmetric structure can achieve right hand circular polarization (RHCP) or left hand circular polarization (LHCP) at 2.6GHz, and symmetrical structure get line polarization(LP) transformation at 2.4GHz. The experimental result shows that the proposed antenna has an impedance bandwidth of 2.20～2.80GHz (600MHz) and 3dB CP　band－width of about 100 MHz at CP modes, an impedance bandwidth of 2.1～2.55GHz (450MHz) at LP mode. This proposed antenna is suitable for wireless mobile communication, etc.