Taking residential buildings as the study objects, for three different residential load types such as low load, medium load, and high load type, indoor thermal environments of different load sharing-rates are simulated, respectively. Indoor thermal comfort and indoor air quality of different load sharing-rates are also analyzed and evaluated. And the appropriate range of cooling load sharing-rates are given from the view of both occupants thermal comfort and occupants health. When ωc (the sensible heat load sharing rate of the radiant terminal device) <0.7, the human thermal index in work region can be controlled within the range of thermal comfort standard. From the point of avoiding local discomfort, ωc is suggested to take 04~1. As regard to indoor air quality, for the constant air volume mode, ωc is suggested to take 0.5~0.9 under low and middle load conditions, and ωc is suggested to take 0.35~0.6 under high load conditions. For the variable air volume mode, the smaller the value of ωc is, the better indoor air quality is.