The structures of the cubic, the tetragonal and the orthorhombic phases of single crystals of the ferroelectric aluminate sodalite Sr/sub 8/(Al/sub 12/O/sub 24/)(CrO/sub 4/)/sub 2/ were investigated by selected area and convergent beam electron diffraction in the temperature range between 180 and 370 K. Evidence was obtained for the non-centrosymmetric character of the cubic phase which infers the space group I43m. The electron diffraction analysis points to the following phases I43m, P4/sub 2//mmc and Ama2.