In this study, effects of ultra-dispersed nanodiamond content on the microstructure and wear properties of Cu-15 wt.% Ti matrix composite were investigated. Samples were prepared by mechanical alloying and sintering at 890• C for 2 h under H2 gas atmosphere. Microstructural changes and dry sliding wear characterizations of sintered samples were investigated by a field emission scanning electron microscope (FESEM), and their phase characteristics were carried out using X-ray diffractometer (XRD). Electron microscopy investigations revealed that a good bonding between nanodiamond particles and Cu matrix could not be maintained due to the formation of free copper layers and the presence of high oxygen amount at the interface. The results taken from worn surfaces showed that high content of nanodiamond (10 wt.%) with oxide particles led to low wear resistance due to poor bonding between Cu-15 wt.% Ti matrix and nanodiamond particles which were pulled out during dry sliding wear.K e y w o r d s : ultra-dispersed nanodiamond powders, microstructure, wear resistance