In this paper, experiments and simulations for moisture buffering of the gypsum boards is described. The small chamber (4.62 m 3) installed the gypsum board on the interior surface was used for the experiments. This chamber was located in a climate chamber. The ambient condition of the small chamber was controlled at constant temperature and humidity. In the experiment for the relationship between moisture buffering and ventilation rate, three cases of ventilation rate, i.e. no ventilation, 1.0 1/h and 5.0 1/h, were investigated. In the experiment for the relationship between moisture buffering and volume rate of the materials, various area and locations of the gypsum boards on the surrounding walls was investigated. Simulations were also carried out to compare with the measurement results. Experimental data set for boundary conditions, i.e. ventilation rate, amount of moisture production, ambient air temperature and humidity, were provided as input data for simulations. Six simulation programs participated in this project. Simulation results in some of cases indicated comparatively good agreement with the measurement results. However, deviations between experimental values and simulation results in other cases were large.