A sintering procedure in constant heraus muffle furnace was carried out at an \ninterval of 1600-1900 oC for 50 min dwelling time and 5 oC min-1 cooling rate to improve the \ngrain growth of magnesia. The effects of temperature on the grain growth and microstructural \nexamination of samples were investigated by using Scanning Electron Microscopy (SEM). \nThe average grain size was also determined separately by an intercept measurement method. \nAccording to the findings, crystal size and bulk density were enhanced significantly as a \nlinear relationship with the increasing temperature. For the samples sintered at 1900 oC, a \nmaximum average grain growth (~100μm) has been obtained. In this paper, the effects of \ntemperature on the crystal size and bulk density of the treated magnesia and its marketability \nwere evaluated.