A novel compact reconfigurable microstrip antenna with agile polarization is proposed. Two small orthogonal notches near opposite angles of the square patch are cut. A PIN diode is placed on every notch and is used as switch to change the current distribution. By controlling two switches, the antenna can operate on left-hand, right-hand and linear polarizations. This antenna is designed, fabricated and measured. Measured results are better than simulated ones by HFSS. Experimental results show that S11 less than −10dB for two circular polarization are both about 470MHz (5.27–5.74GHz) and bandwidth of AR less than 3 is about 110MHz with minimum value of 0.65dB. Good directivity and about 6.5dB gain are obtained.