Abstract The object of this report is to grasp the fundamental factors involved in the cement solidification treatment of industrial wastes containing heavy metal compounds such as oxides, hydroxides and sulfides of Cr, Cu, Zn, As, Cd, Hg and Pb. Cement mortars adding heavy metal compounds were made, ordinary temperature curing or autoclave curing were taken as the conditions of solidification treatment, and the hardening property and leaching behavior with respect to water or artificial sea water were investigated.