Diamond/Cu-xCr composites were fabricated by pressure infiltration process. The thermal conductivifies of diamond/Cu-xCr (x = 0.1, 0.5,0.8) composites were above 650 W/mK, higher than that of diamond/Cu composites. The tensile strengths ranged from 186 to 225 MPa, and the bonding strengths ranged from 400 to 525 MPa. Influences of Cr element on the thermo-physical properties and interface structures were analyzed. The intermediate layer was confirmed as Cr3C2 and the amount of Cr3C2 increased with the increase of Cr concentration in Cu-xCr alloys. When the Cr concentration was up to 0.5 wt.%, the content of the Cr3C2 layer was constant. As the thickness of the Cr3C2 layer became larger, the composites showed a Iower thermal conductivity but higher mechanical properties. The coefficients of thermal expansion (CTE) of diamond/Cu-xCr (x = 0.1, 0.5, 0.8) composites were in good agreement with the predictions of the Ker’ model.