This paper presents a novel microstrip three-mode filtering power divider (FPD) with high frequency selectivity and high isolation, which integrates only a single resonator and a resistor to realize the dual functions of the power division and filtering. In order to further improve its frequency selectivity and obtain wide upper stop band, three open stubs are loaded into the input and output ports of the filter power divider. The measured and simulated results show that the range of S 11 < −10 dB is 1.86 ∼ 2.1 GHz; the relative bandwidth of 3 dB is 17.9%; the in-band isolation is higher than 26 dB; and it has a relatively simple topology.