Abstract: The whole social electricity demand in an area is analyzed to find the relationship between the whole social electricity demand and electricity consumption of various industries. The principle component analysis on regional industry electricity consumption index is carried out based on SPSS, and the principle component factors of electricity consumption of several main industries (some variables) are found. Then the principle component factor and whole social electricity demand is analyzed by using of regression analysis method, and electricity demand model is built. The example shows that better forecast results of whole social electricity demand are obtained based on few industry electricity consumption.