We report the Yb,Er,Eu:YAP laser crystals with three different Eu³⁺ do ping concentrations grown by the Czochralski method and investigate their spectroscopic characteristics.The abso rption spectrum in the range of 320-3000nm is measured,and there is strong absorption and w ide absorption band around 978nm.The fluorescence spectrum and decay curves are measured by the excitation of 975nm LD and OPO laser,respectively.The level lifetime is obtained with single exponential decay.These parameters are compared with tho se of the single doped Er:YAP crystal and the sensitization and deactivation mechanisms are analyzed.The results indicate th at the Yb³⁺ and Eu³⁺ ions can act as sensitizer and deactivator for Er³⁺ ions,respectively,resulting in the wid ening of the absorption band at 978nm and decreasing of the lifetime ratio (4.1,3.1and 2.7) between the lower laser leve l (⁴I13/2) and upper laser level ( 4I11/2). However,the lifetime ratio of single doped Er:YAP is very high and up to 10.8, which is disadvantageous to the improvement of the laser output properties.Therefore,the new Yb,Er,Ho:YAP laser crystal is mo re suitable to be pumped by 970-980nm LD laser and the 2.7-3.0μm laser output could be realized easily with lower l aser threshold and higher laser conversion efficiency.