Abstract: C/C composites with excellent thermal/electrical conductivity were prepared from chopped mesophase pitch-based carbon fibers and mesophase pitch by a series of processes including molding, carbonization, densification and graphitization. The influences of mesophase pitch content on the densities, thermal/electrical conductivity and XRD crystalline parameters were studied. The relationship between microstructure and properties of the composites is also discussed. Results indicate that the mass ratio of mesophase pitch to fiber had a great impact on conductivity and microstructure of the composites. With increasing mesophase pitch binder content up to a mass ratio of 0.8, the interlayer spacing (d002) decreased while the crystallite size parameters (La, Lc) and conductivity of the composites increased. At this point a composite was prepared with in-plane thermal conductivity of 385W/m·K and electrical resistivity of 2.85mW·m. For higher mass ratios the interlayer spacing continued to decrease, while the crystallite size parameters and conductivity decreased.