[en] Dielectric, dilatometric measurement and polarized microscopic observation were performed for single crystal of CsCdBr₄. These investigations showed clearly the phase transitions at 252 K, 236 K and 153 K. The jump-like change in crystal volume corresponding to the first-order phase transition was found at temperature of 236 K. Ferroelastic domain structure was observed along the a-axis below 236 K and it is presented below the transition at 153 K. Observation along the c-axis revealed new domain structure below 153 K. (author)