A high-power and highly-frequency-stabilized laser has been developed for the laser interferometric gravitational wave detector. Requirements of the light source for this are a single transverseand longitudinal mode with the power and frequency noise of 10W and 10^-6Hz√Hz at 300 Hz, respectively. The frequency of a LD-pumped injection-locked Nd: YAG laser was stabilized to a high finesse Fabry-Perot optical resonator that was isolated from seismic and acoustic noise, which was achieved by controlling master laser light. We evaluated the mechanical and thermal stability of Fabry-Perot cavities of both rigid spacer type and the independently suspended mirrors type. Finally we have achieved the absolute frequency noise of2×10^-2Hz/√ Hz for an injection-locked high-power laser with the output power of 9.8 W.