����������������������������������������������� � � � In order to estimate the effect of evaporative cooling pavement system on the thermal environment of urban spaces, a heat and water balance model for a thermal environment simulator was developed in this paper. An outdoor experiment showed that the porous pavement surface got moist from evening to next early morning. It was confirmed that the main causes of the phenomenon were capillary condensation on the pavement surface and equilibrating of vertical water content distribution of the pavement inside. Heat and water balance factors on the pavement surface were formulated based on these experimental data, and the calculation accuracy of the model was checked through comparison with the experimental data in summer. �