A novel broadband dual-polarized slot antenna with stable radiation pattern is presented. Two U-shape microstrip lines are introduced at two feeding ports to excite a cross-shape slot for realizing dual-polarized antenna. The simulated results are given to explain how the ground plane, short metallic pillars, and reflector affect the reflection coefficient, |S11|. The beamwidth of the proposed antenna is stable within the operating band, whereas a broad fractional bandwidth (|S11| < ?10 dB) up to 68% is achieved, covering a frequency range of 1.3–2.65 GHz. The measured half-power beamwidth of H-plane is 66.8° ± 3.4°.