A short introduction was given about the principles of laser guide star (LGS) in adaptive optics, and the ultra-narrow band filter techniques used in the application. The techniques which would be possible to be used in laser guide star were presented in detail, such as atomic resonance filter, birefringent filter, Faraday anomalous dispersion optical filter and Fabry-Perot filter. Based on the characteristics of each technique, the principles and major parameters were illustrated. Also, the disadvantages and state of each technique were elucidated.