Mg-Sc alloy has a body centered cubic (bcc) phase at high temperature beside an hexagonal close packed (hcp) phase in the Mg-rich region. In this study, we investigated the effect of a heat treatment process on the texture formation of an hcp single-phase in Mg-Sc alloy by means of electron backscatter diffraction. It was found that a random textured hcp single-phase could be obtained by phase transformation from a bcc single-phase to an hcp single-phase and that the texture did not depend on the grain size.