This paper describes an extensive laboratory-based investigation into the use of fly ash and fine tailings in one type of insulation materials of building materials-foamed concrete.Foamed concrete with apparent density from 500 to 1 000 kg/m3 , compressive strength from 1 to 14.5 MPa and thermal conductivity from 0.06 to 0.145 W/(m · ℃) were prepared when a large volume of cement(up to 60 wt.%) have been replaced with fly ash and fine tailings.The rheologic, mechanical and heat preservation properties were investigated for the foamed concrete.The results shows that using fly ash and fine tailings can significantly enhance the theologic property of fresh foamed concrete.In addition, up to 60% of the cement could be replaced without obvious reductions in long-term strength and thermal conductivity in relative higher density(1 000 kg/m3).By using fly ash or fine tailings as fine aggregate in foamed concrete, the high volume utilization of these industrial waste becomes possible, thus providing a means of economic and safe disposal of these waste residues.