The purpose of this paper was to investigate the effective use of the minimum outdoor air ventilation rate using computational fluid dynamics(CFD)methods in residential buildings with low cooling load,where a chilled ceiling in combination with a fresh air handling unit was adopted.Some thermal environment parameters such as air speed,temperature,relative humidity,concentration of pollutants were obtained under three kinds of air distribution such as mixing ventilation,displacement ventilation,underfloor air supply.And the comprehensive evaluation of the indoor air quality and thermal comfort level of three kinds of air distribution were also given.The results show that when displacement ventilation or underfloor air supply is adopted,the better indoor air quality will be obtained,and the minimum outdoor air ventilation rate will be used more efficiently.