Aimed at the anisotropic characteristic of metamaterials, the propagation modes and the propagation conditions of metamaterials are analyzed. Through superposing the vector coordinate axis and the physical space coordinate axis, and introducing the parameter of the wave propagation angle, the dispersion relation of biaxial anisotropic metamaterial is derived. Based on the wave propagation angle, four classes of medium are identified as:①kz-cutoff type;②kx-cutoff type;③Never-cutoff type;④Always-cutoff type. This classification makes the propagation mode of electromagnetic wave take on more intuitionistic effect. The characteristics of refraction and reflection of metamaterials are analyzed by the wave vector curve, simulated and verified by using the dispersive finite difference time domain method. The numerical results well conform to the theoretic analysis.