The　physical　and　mechanical　properties　of　coal　gangue　aggregate　were　investigated　firstly,　and　then　the　microstructure　characteristics　of　different　kinds　of　coal　gangue　aggregate　were　analyzed.　The　mechanical　property　of　concrete　containing　coal　gangue　aggregate　was　also　measured.　The　results　show　that,　the　main　composition　of　coal　gangue　is　SiO2,　which　may　result　in　ASR　damage　of　concrete.　The　SEM　experiments　indicate　that,　pore-structure　of　coal　gangues　aggregate　is　different　from　that　of　natural　aggregate,　and　the　microstructure　of　natural　aggregate　is　more　homogenous　than　that　of　coal　gangues　aggregate.　Coal　gangue　aggregate　will　not　obviously　affect　the　performance　of　concrete　containing　coal　gangue　aggregate　when　the　content　of　coal　gangue　aggregate　is　limited　to　some　extent.