The building electricity energy consumption models were established based on the analysis of building electricity energy consumption.Data were collected by hours about the office equipment energy consumption,lighting energy consumption and number of people.Investigations were made into the building management modes.Based on the collected data,a close relationship between equipment electricity energy consumption and number of people was found and the linear regression model was then developed.Lighting energy consumption was found to be related with number of people and solar radiation intensity,but the relationship was nonlinear.A classification model was developed with the decision tree algorithm.With the models,electricity consumption can be predicted hourly and the impact of building management mode on power demands can be assessed.