Fly ash particles reinforced aluminum matrix composites were fabricated by powder metallurgy method. The influence of different fly ash content on hardness, the friction and wear behavior of the composites were investigated at a constant sliding velocity of 400r/min. The worn surfaces of composites were observed by scanning electron microscope, and worn mechanism of composites was discussed. The results showed that the hardness of composites increased first and then decreased with fly ash content increasing. Under the lower loads and at the lower fly ash content, the friction co-efficient is steadily lower than that of Al alloy matrix. The wear resistance of composites increased with the volume fraction of fly ash particles and the wear mechanism was characterized as abrasive wear and adhesive wear.On the other hand, the wear mechanisms in the composites have been transformed with increasing load and fly ash volume; it mainly was delamination wear and abrasive wear.