Based on the structure of the cube corner retro-reflector (CCR) and the optical properties of directional reflection, it is demonstrated the symmetry relationship between emergent point and the incident point of the same beam, and the offset relationship between projection point of vertex of a CCR and emergent point of different beams. It deduces the formula for calculation of the maximum incident angle and the effective reflection area of a CCR with different incident conditions, appearing law graphs of the maximum incident angle changing with different azimuth angle and refractive index and the effective reflection area changing with different incident angles, azimuth angles and refractive indexed.