Diamond/Ag–Ti composites were fabricated by a low-cost liquid sintering technique. The Ti addition can effectively improve wetting and promote penetration in composite pores during liquid sintering. The interface structure of the diamond/Ag–Ti composite was identified as Ag/TiC/Ag–Ti/diamond. A high thermal conductivity of 719W/mK was obtained for the 50vol.%diamond/Ag-1at.% Ti composite. Using a bimodal mixture (60vol.%150μm+10vol.%50μmdiamond/Ag-2at.% Ti composite), a low coefficient of thermal expansion of 6.3×10 −6 /K still with high thermal conductivity of 687W/mK was achieved. These composites have potential applications for thermal management of high integration electronic devices.