Abstract:The influence of fineness and content of coal gangue on the properties of cement pastes was studied.The results show that the fluidity of the cement pastes reduces with the increasing of fineness and content of coal gangue,but the setting time prolongs.The compressive strength and the chemically combined water content of the hardened cement pastes continuously increase with improving fineness of coal gangue during curing age.But they decrease with increasing the content of coal gangue.The fineness and content of coal gangue have also influence on the pore distribution and SEM figure of the hardened cement pastes.