In this paper, the effect of a lime-stone powder and a super plasticizer on the some characteristics of building gypsum binder, which was produced from natural gypsum, is obtained. Study results show that: a lime-stone powder on advantage contents mixed with this binder increased the compressive strength and reduced the setting time and as the mixed water content. Super plasticizer reduced the setting time of this binder. The combined use of these admixtures on building gypsum binder has a high effect on compressive strength.