This article elucidated with the primal presenent of the theory of Laser.On the historical process of Maser and Laser is described and more compl-etely expose the present and direction of Laser.

• 本文论述了激光器理论的早期提出、量子放大器和激光器的发明历史,并简要分析了激光器的现状和今后的发展趋势。