A new mixed orthophosphate crystal of Yb0.05:Lu0.03Y0.92PO4 was grown by high temperature solution method. The crystal structure, polarization absorption and emission spectra, and fluorescence lifetime were measured and investigated in detail. Continuous-wave (CW) laser action of the mixed crystal was achieved in a simple plane-parallel resonator under diode pumping, producing a maximum CW output power of 0.81 W with a pump power of 2.18 W, the slope and optical-to-optical efficiencies being respectively 46.4% and 39.6%. The wide emission spectrum of the mixed crystal also indicates that it may be of some potential applications in the generation of mode-locked femtosecond pulsed lasers.