Since　steel-concrete　composite　structure　has　more　advanced　technical　and　economic　indices　than　both　steel　and　reinforced　concrete　structures,　it　is　widely　applied　in　engineering　structures,　especially　in　bridges　in　recent　years.　As　bridges　are　subjected　to　fatigue　loads　of　the　vehicles　frequently,　thus　it　becomes　more　and　more　important　to　investigate　fatigue　mechanisms　of　composite　structures,　especially　composite　decks.　In　this　paper,　the　basic　concepts　and　principles　of　fatigue　are　briefly　introduced,　and　then　an　overview　of　the　fatigue　performance　for　steel　structure,　reinforced　concrete　structure　and　steel-concrete　composite　structure　is　made.　Finally,　existing　problems　of　fatigue　for　composite　structures　are　discussed　and　the　prospect　in　the　future　forecasted.　The　study　shows　that　damage　accumulation　mechanism,　damage　identification　and　reliability　of　fatigue　are　investigated　in　emphasis　in　the　future.