An experiment was performed to simulate an air cooling panel system for passive decay heat removal from a high-temperature gas-cooled reactor to investigate the performance of decay heat removal and the temperature distributions of components of the system. The experimental apparatus consisted of a pressure vessel 1 m in diameter and 3 m in height, bristling with nineteen simulated stand pipes atop and containing heaters with the maximum heating rate of 100 kW which simulated residual heat of the core, and cooling panels surrounding the pressure vessel. The analytical code THANPACST2 was applied to the experimental data to investigate the validity of the analytical method and model proposed. Under the conditions of helium gas at the pressure of 0.64 MPa and temperature of 514°C in the pressure vessel, the temperature distribution of the pressure vessel was properly estimated within differences of -10 to +50°C compared to the experimental data. The analysis indicated that the heat transferred to the cooling panel was 15.4% less than the experimental value.