Growth of nitride crystals has been tried in a supercritical nitrogen fluid at high-pressures (about 10 GPa) and high-temperatures yield using diamond anvil cell and YAG laser heating system. Colorless transparent fine crystals of GaN in the wultz-rock type structure have been grown from molten gallium and fluid nitrogen at 10 GPa and high temperatures. They have hexagonal platelet or prismatic morphology, indicating a solution growth using supercritical nitrogen fluid as solvent. The results in this study open us a new way of crystal growth of not only GaN but also various kind of nitrides in a supercritical nitrogen fluid under high-temperatures and high-pressures yield using diamond anvil cell and YAG laser hearing.