Spectroscopic properties and cw laser performance of a new Yb0.0054:Y0.3481Gd0.6465VO4 mixed crystal are reported. A sizable bistability is displayed in the laser operation with a bistability range of 1.9-3.4 W in terms of absorbed pump power, in which the coexistence and switching of the sigma and pi polarization states occur accompanied by wavelength shifting upon decreasing the pump power.