A power generation system having a gas turbine engine that utilizes sunlight, includes a compressor configured to compress an air which is a working medium, a solar heater configured to heat the air compressed by the compressor, utilizing sunlight as a heat source, a hydrogen combustor configured to burn the air compressed by the compressor utilizing hydrogen as a fuel, a turbine configured to output a motive power from a high-temperature gas heated by at least one of the solar heater and the hydrogen combustor, a power generator configured to be driven by the turbine, and at least one hydrogen-generating unit configured to generate hydrogen by utilizing an output of the turbine or exhaust heat from the turbine to decompose a water, and supply the hydrogen so generated to the hydrogen combustor.