Superplasticity is a phenomenon that occurs in a material, which in certain conditions, at the strain rate and temperature, can show very high ductility and deformation. Superplasticity declares the strain extension between 100 – 1000 %. The purpose of this research was to obtain a composite material properties of superplasticity in Al 6061 reinforced by bottom ash coal. This research used uniaxial tensile test at high temperature. The variable parameters of this research are temperatures (500, 550, 600 °C) and tensile speed (10-5, 10-6, 10-7 m/s). The result of this research is the defined maximum extension of 200% at 600 °C, with tensile speed at 10-7 m/sec.