Indoor design air parameters regulated in current design standards are set on the basis of human thermal comfort without fully considering the building energy efficiency. This article analyzed the indoor design air parameters with investigation study and simulation study respectively from both views of thermal comfort and energy consumption. By conducting field testing in existing buildings and collecting design information from blueprints and description files, indoor air parameters of 140 public buildings in China were investigated. Typical public buildings (small office building, large office building and shopping mall) were selected for simulation study. Simulation models for three types of public buildings were established based on the investigation results in order to have assumptions better fit the actual situations. The relationship between PMV (predicted mean vote) and energy consumption of the simulation models was analyzed. From the analysis of the results of investigation and simulation, it could be seen that the design relative humidity in winter hardly influences the indoor thermal comfort and building energy consumption, while design relative humidity in summer, indoor air temperature and PMV values were all related to indoor thermal comfort level and building energy consumption. Recommend indoor design air parameters that contribute relatively low energy consumption and high comfortable level were also put forward to improve the current design standards. (c) 2012 Elsevier B.V. All rights reserved.