A　calculation　model　for　fatigue　damage　of　graphite-matrix　interface　of　austempered　iron　was　proposed　by　using　system　analysis　method.　The　parameters　of　fatigue　damage　was　obtained.　Three-point-bending　fatigue　test　was　applied　to　investigate　the　fatigue　damage.　The　results　of　the　test　revealed　that　the　system　analysis　method　is　effective　and　can　specify　the　cracking　in　the　graphite-matrix　interface,　the　initial　fatigue　cracking　and　the　whole　propagation　process　are　influenced　by　cyclic　loads　extremely.