As high as 20 at% Yb3+-doped YAlO3 (or Yb:YAP) single crystal with the typical size of 0 30 X go mm(2) has been successfully grown by RF-heated Czochralski method. The perovskite-type structure of 20 at% Yb:YAP crystal was refined by the precise XRD measurement. The absorption and emission spectra of the H-2-annealed 20 at% Yb:YAP crystal were investigated at room temperature. Besides the typical IR emission originating from the F-2(5/2) --> F-2(7/2) transition of Yb3+ ions in YAP host, the visible up-conversion fluorescence excited by 940 nm LD source was also observed in the 20 at% Yb-doped YAP crystal. The X-ray excited luminescence features of the 20 at% Yb:YAP crystal were also investigated at the room temperature, and the fast charge transfer luminescence with the emission peaks at 364 and 530 nm were clearly identified, which indicates that the highly doped Yb:YAP crystal can be served as the promising fast scintillation crystals. (C) 2004 Elsevier B.V. All rights reserved.