Spark plasma sintering (SPS) was used to weld the ceramics,eg, Cr3C2 and metal, Ni in this paper. It is found that the SPS can weld the Cr3C2 and Ni plates at lower temperatures and shorter holding time comparing with that of hot-pressing (HP). The binding strength was 113 MPa when the temperature was 1000℃by SPS, compared with 10 MPa by HP at the same temperature. SPS remarkably enhances the atom diffusion in welding.Thermodynamics analysis at different welding temperatures and holding times of SPS or HP shows that the local temperature gradient, different from the past effects of by-passing current, is the dominative mechanism of the SPS welding.