The thermoluminescence (TL) properties of high quality 0.5% atom fraction Cu doped YAP crystal (YAP:Cu) which is grown by medium-frequency induction Czochralski method is systematically studied by RisF TL/OSL–DA-15. The research results show that, YAP:Cu crystal has two TL peaks which locates at 431K and 482K, and the 482 K peak is the main glow peak. The peak position does not shift with the change of irradiation dose and belongs to the first- order peak. The TL response of YAP:Cu crystal shows excellent linear characteristics in the dose range of 10- 5- 102 Gy. YAP:Cu crystal is a potential ionization irradiation dosimetry material with excellent TL properties.