There are humidity problems in rural residence in hot and humid areas and condensation occurred on the ground, which affects indoor living quality and health of residents. The basic way to control the ground condensation is to improve the ground temperature, and to determine the thermal performance of the ground. In this paper, thermal and moisture parameters as well as ground temperature of rural residence in Chongqing were measured and the rural residence model was established for simulating damp proof function of overhead ground and insulation ground. The results show that the effect of overhead ground on the damp proof is significant. It could reduce the time of condensation on the ground by more than 90%. Based on the fact that the effect of overhead ground on damp proof is widely accepted,it is proposed that the low thermal resistance of insulation ground for damp proof is 0.5 m²·K/W.