Abstract: The background and scientific goals of lunar/relay-satellite laser ranging is introduced. The current status and development trends of laser ranging is presented. The mission design is discussed,mainly including the manufacture of a single 170-mm-aperture Corner-Cube Retroreflector(CCR)a the laser ranging system based on a 1.2-m telescope installed at the Kunming station of Yunnan Observatory. A pulse laser with pulse width of 10ns and pulse energy of 3 J is used. The received photon number of 0.74 is expected,and the ranging precision is better than 1 meter.