Abstract: This study revealed the reliability of degree days for reflecting the office building energy consumption by simulating the energy consumption from 1961 to 2012 and then investigating the correlations between the heating and cooling energy consumption and degree days in four cities including Harbin,Tianjin,Shanghai and Guangzhou representing different climate zones in China.The results show that there are significantly linear positive correlations between the heating energy consumption and heating degree days in Harbin,Tianjin and Shanghai and degree days can explain up to 95% variations of heating energy consumption,implying that heating degree days can be efficiently used to reflect the characteristics of the heating energy consumption and therefore to study the impact of climate change on heating energy consumption.On the contrary,the cooling degree days are unable to accurately reflect the variations of cooling energy consumption.By analyzing the relationships between energy consumption and relevant climatic factors,the heating energy consumption is dominantly affected by the temperature in winter while the cooling energy consumption is related to various factors such as temperature,humidity and radiation in summer,especially in the cities of hot climate zone.