The supercritical carbon dioxide (S-CO2) Brayton cycle has been receiving worldwide attention due to the high thermal efficiency and simple system configuration. Differ from the conventional steam Rankine cycle, the S-CO2 Brayton cycle operates without phase change such as condensation process. Therefore air-cooled system can be considered as waste heat rejecting system. Furthermore a power plant can overcome site limitation with air-cooled system, so KAIST S-CO2 research team suggested an air-cooled S-CO2 power cycle for desert climate. A combined cycle gas turbine (CCGT) power plant, which utilizes waste heat of gas turbine for bottoming cycle, was re-evaluated with various S-CO2 bottoming cycles. Compare to the reference steam Rankine cycle, the S-CO2 power cycle showed better performance as a bottoming cycle. In this study, the comparison of various S-CO2 cycles for waste heat recovery system and the applicability of S-CO2 power cycle with air-cooled system for desert climate are covered.