The heat and moisture states of building floors without impermeable boundary construction, which affect the indoor thermal and moist environment, are determined by the heat and moisture distribution features and coupled transfer process of the under-soil and groundwater level. Previous studies based mainly on mathematical models only considered heat transfer or simplified the boundary conditions as adiabatic and impermeable, which resulted in limitations in application, specifically greater errors in shallow groundwater areas. In this paper, a scale model experiment that combined the floor, soil and groundwater was conducted to study the affected degree of the thermal and wet conditions of the floor in terms of the combined effect of soil heat and moisture transfer and indoor thermal and moist environment. The results showed that under the influence of the latent heat of vaporization, groundwater increases the floor temperature in the short term, and under the influence of water vapor pressure, groundwater decreases the relative humidity of the floor in the short term. The influence range of underground moisture source, analysis of building energy consumption"effected by underground moisture source, process of ground surface hot and humid states reaching equilibrium, were discussed by numerical calculations. (C) 2017 Elsevier B.V. All rights reserved.