Abstract: In order to compare the tribological properties of two aluminum matrix composites reinforced by different content of B4C particles,the pin samples were prepared with them and friction and wear tests of pin-on-steel disc were carried out on a multifunctional tribometer.The influences of contact load and sliding velocity on friction and wear performance of two composites were expressly investigated.The result show that the wear mass loss of the aluminum matrix composites reinforced by B4C particulates increased with the increase of contact load and sliding velocity.The friction coefficient of the composite pin vs steel disc decreased with decreasing contact load and sliding velocity.The wear resistance of higher content of B4C particulate composite was better than that of lower content of B4C particulate composite.