Glass ceramics was made by the one-time sintering method using the main raw material of iron tailings.On the basis of quaternary system of CaO-MgO-Al_2O_3-SiO_2,using DTA, XRD and SEM,the effects of different nucleating agents and mixing amounts as well as heat treatment on the crystallization of tailings glass ceramics were studied.The experimental results show that,nu-cleating agent and heat treatment are two necessary conditions for one-time sintering preparation of tailings glass ceramics namely,only adding nucleating agent or experiencing heat treatment,the qua-ternary system can not crystallize.The composite nucleating agent consisting of Cr_2O_3 and TiO_2 can further lead to the crystallization of the CaO-MgO-Al_2O_3-SiO_2 quaternary system at the lower tem-perature,with the major phase of diopside.In the range of mass content,0%-4%,crystal intensity and crystal content grow.But when mass content is more than 4%,the crystal size will become coarser and the crystal distribution will be less regular.Different heat treatment regimes do not change the com-position of the crystalline major phase in the glass ceramics crystallization of CaO-MgO-Al_2O_3-SiO_2 system.In the range of 30-60 minutes,with the extension of nucleation and crystallization,crystalli-zation degree enhanced,but if the holding time surpasses 60 minutes,the crystallization is worse.