The basic theory of laser surveillance is discussed. The characteristics ofwaveforms reflected by the targets working with staring and scanning style are analyzed. The pulse laser can be used to detect targetsworkingwith staring style. The CW laser modulated with mono－frequency can be used to detect targets working with scanning style.The method of detection and recognization to the signal is analysed in two differentworking styles. It is p roved in experiments that the wanted results can be realized in such methods.