The influence of styrene-butadiene rubber（SBR） latex content on the rheological properties， hydration heat release， and hydrates of sulphoaluminate cement（SAC） was investigated. The results show that if the SBR latex content is more than 20%， with increasing SBR latex content， the solid content of cement paste increases， and the agglomeration and adherence of the polymer are accelerated. It improves yield stress and plastic viscosity， shortens the setting time， and increases hydration heat release of cement paste. The content of ettringite gradually increases with the increase of SBR latex content. Therefore， high use level of SBR latex can promote the early hydration of SAC.