A compact power divider with ultra-wideband (UWB) quasi-Chebyshev filtering response is proposed in this paper. By employing slotted microstrip cross-junction and hybrid slotline/ microstrip resonator, a UWB passband and wide isolation can be realized simultaneously. A perfectly matching is obtained by analyzing the equivalent circuits of even/odd mode. Then, a quasi-Chebyshev filtering response is theoretically realized by using the modified 2-port transmission-line (TL) network with asymmetrical port impedances. To verify our new approach, a prototype UWB PD operating at 3.1-10.8GHz is designed, the fractional bandwidth of the proposed PD is 110% (-15 dB return loss). Simulated results show good agreement with theoretical analysis.