This Letter presents a compact microstrip diplexer. The high-frequency signal path is constructed by two electrically-coupling half-wavelength resonators, its external coupling adopts the tapped line structure. The low-frequency signal path is formed by two magnetically-coupling quarter-wavelength resonators, its external coupling is accomplished by microstrip coupling lines, which are formed from the tapped line structure and resonator of the high-frequency signal paths. The novel combination of the two signal path removes the need of T-junction in conventional diplexers. Meantime, the coupling strength of the two pass bands at the input port can be separately designed. A diplexer with Chebyshev frequency response at both signal paths with the central frequencies of 1.8/2.4 GHz is designed, fabricated and measured. The measured results give a good agreement with the simulated ones, which verifies the effectiveness of the diplexer.