Abstract: Calcium-silicate slag is a kind of solid waste，which is discharged during alumina extraction from high alumina content fly ash.To reveal the performance of calcium-silicate slag based eco-cement，regarding 32.5# ordinary Portland cement as a reference object，natural sandstone as aggregate，and liquid polyethylene acid as reducing agent，concrete at the degree of C30 & C40 were produced，and also its mechanical properties and durable performance were investigated.The results show that ①the mechanical properties of the calcium-silicate slag based eco-concrete at early age are better than those of the ordinary Portland concrete，but at slow growth in the late.The flexural strength and the compressive strength of the eco-cement mortar cured at 28d reach more than 8 MPa and 40 MPa，respectively.②Compared with ordinary concrete，eco-concrete confers excellent properties of the resistance to sulfate attack and chloride penetration.Eco-concrete cured at 14 d (including 14 d)is about the same to ordinary Portland concrete，but its shrinkage is less than ordinary Portland concrete after 14 d.Eco-cement C40 has excellent resistance to alkali-aggregate reaction.The remaining durable performance of eco-concrete is fairly the same as that of ordinary Portland concrete.③Eco-cement has excellent solidification characteristics for Cr ions.Therefore，eco-cement is superior to the ordinary Portland concrete.

Key words: Calcium-silicate slag based eco-cement, 32.5# ordinary Portland cement, Concrete, Mechanical properties, Durable performance