With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were studied through collection of verified data in site visits and field tests.The result revealed that,electricity accounted for 99.79％ of the total energy consumption,natural gas 0.17％,and diesel 0.04％.The air conditioning dominated the energy use with a share of 43.18％,equipment in the particular areas 26.90％,equipment in the office rooms 11.95％,lighting system 8.67％,general service system 7.57％,and miscellaneous items 1.73％.Statistical method including six indicators obtained the energy consumption benchmark with upper limit of 98.31 kW·h/m2 and lower limit of 55.26 kW·h/m2.According to ASHRAE standard(comfortable standard)and GB/T 18883-2002(acceptable standard),the indoor environmental quality of 51 sampled office buildings was classified into three ranks:good,normal and bad.With benchmark of building energy consumption combined with indoor environmental quality,it was found that only 3.92％ of sampled buildings can be identified as the best performance buildings with low energy consumption and advanced indoor environmental quality,and the buildings classified into normal level accounted for the maximum ratio.