TL glow curve of any semiconductor is the patterns that mean when a material is suitable as Thermoluminescent (TL) material. Gadolinium aluminate (GdAlO3) perovskites have several properties that can be propose it as a good host for thermoluminiscent materials. GdAlO3 perovskite powder was synthesized by coprecipitation method and the powders were analyzed by characterization techniques. The Differential scanning calorimetry study showed changes in crystalline phases at 900 °C and 1084 °C during the calcination process. The first change of crystalline phase was identified by X rays diffractometry technique as a change from GdAlO3 hexagonal to GdAlO3 orthorhombic. TL glow curves of GdAlO3 under ultraviolet (UV) 256 nm and beta radiation effects were observed as crystallite size was increased.