The prepared n-Cu particles with the particle size about 20 nm by KBH4 reduction method in aqueous solution was surface modified using silane coupling agent. The surface modification mechanics was researched. The tribological performances of n-Cu particles were tested by friction wear test machine. The results show that the modified n-Cu paritcles by silane coupling agent have high purity, good dispersion performances and wonderful surface activity. In friction process, the modified n-Cu particles can form a layer of organic-inorganic compound film with synergistic effect on worn surface, which improves the tribological performances of friction material.