A multi-mode wideband antenna based on multi-mode resonator is proposed with stable radiation patterns, which is composed of metal radiators, parasitic resonators, shorted patches fed by the U-shaped feedline, and a box-shaped reflector. A prototype of the proposed antenna is designed, fabricated, and tested. Measured results show that the antenna achieves an impedance bandwidth of 37.5% (0.67–0.98 GHz) for |S11| < −15 dB, a half-power beam width (HPBW) of 67.5 ± 2.4 degree at H-plane (horizontal plane), and a gain of 8.0 ± 0.5 dBi. Furthermore, the cross-polarization discrimination (XPD) is more than 15 dB at 0 degrees and at least 11.2 dB within ±60 degrees at H-plane, respectively. The proposed antenna can be used in the modern communication systems for LTE700/GSM850/GSM900.