U. S. all services have demonstrated jointly a solid - state laser with the average output power of greater than 25kW and will development 100kW laser for the tactical field by 2008. The technology characteristics of 25kW and 100kW SSL are outlined.The technology features and architectures of Nd∶YAG, SSHCL and Yb∶YAG laser are reviewed and analyzed. The p roblems of SSHCL and Yb∶YAG laser and the challenges of develop ing 100kW Nd∶YAG laser are discussed.Subsequently,the program of a 100 kilowatt－class High EnergyLaser TechnologyDemonstrator is described. Finally, the several views are presented.