Sintered diamond/(WC-Co) composites were prepared by spark plasma sintering technique. Tribological properties were measured at temperatures from RT to $500^{circ}C$ in sliding tests with alumina ball. They show coefficient of friction of 0.1 and below at RT and wear of the diamond composites is hardly detected. Effects of diamond grit size, diamond content and test temperature on the coefficient of friction and the wear are discussed. The wear scars were analyzed.