The yield surface, the mechanical properties and our experimental methods for Zr55Al10Cu30Ni5 metallic glass are explained. The deformation behavior and the yield stress of this material changes for environmental temperature because of its obvious temperature dependency. The effect of normal stress on its yield can be revealed with increasing temperature and the yield surface closes a typical shape based on the Mohr-Coulomb yield criterion. This material also has an obvious strain rate dependency. The experimental study of the influence of deformation speed on the yield surface and function of this material will be important for a practical application of this material under dynamic load in hot environment.