Abstract: The failure mechanism of the automotive engine Oil -pump chain and the worn surface morphology of the rubbing pair of bush and pin were studied .Results showed that the main wear mechanism of automotive engine Oil -pump chain was fatigue wear , and its failure mechanism was the initiation , propagation of cracks and flaking on top layer of pin and bush .Cyclic softening occurred on pin and bush while cyclic hardening occurred on roller .Fretting wear was one of the contributions for failure of automotive chain .The effective ways to increase the resistance to multi -impact were ensuring sufficient strength and plasticity of roller as well as adopting suitable shaping technique.