Abstract: It is emergent to develop new ceramic (glass) matrix composites for modern electronic packaging. Based on copper plating and controlled oxidation of Ti-coated diamond particles, diamond-reinforced glass matrix composites were successfully synthesized by spark plasma sintering (SPS). Their micro-morphology, interface bonding condition, thermal conductivity, and coefficient of thermal expansion (CTE) were investigated. The results show that the composites have uniform microstructure, and the Ti/diamond interface is the weakest in the composites. The thermal conductivity of the composites increases with increasing diamond particle size and content, but the CTE of the composites decreases with increasing diamond content. When the diamond particle size is 100μm and the diamond volume content is 70%, the composite has the highest thermal conductivity about 40.2 W·m^-1·K^-1 and CTE about 3.3×10 ^-6 K^-1,which can meet the requirement of electronic packaging.