Refractory metals 93W and Mo1 were bonded with Ni interlayer by plasma activated sintering. Investigations were mainly focused on the influence of bonding temperatures on the microstructures, elemental distributions across the interfaces and mechanical properties of 93W and Mo1 joints. And fracture mechnism of joints was also analyzed. Reliable bonded joints 93W/Ni/Mo1 were obtained when bonding temperature was above 800℃. Shear strength of 93W/Ni/Mo1 joints firstly increased (650~850℃) and then decreased (800~1000℃) with the rising of bonding temperature, and the maximum strength (100.2 MPa) of joint was obtained at 800℃. Soild solutions were formed at the 93W/Ni and Ni/Mo1 interfaces when bonding temperature was below 800℃, while MoNi brittle phase was emerged at Ni/Mo1 interface which debased the strength of joints. Fracture failure mainly occurs at Ni/Mo diffusion interfaces.