Due to the need forenergy efficiency inindustrial sector, assessment of thefactors affectingenergy intensity seems as an essential task.Inthis study, using panel data approach, the main factorsaffectingenergy intensityinnine branches of Iran's industry during 1374-1389 period were examined. Results show that both energy price and technology are inversely related to the energy intensity. Meanwhile, the results also indicate that the speed of energy consumption (growth of energy consumption) is less than the speed of growing of value added in industries (growth of production) which in turn is indicative of the fact that bigger scale manufactures are more energy-efficient. Therefore, we recommende the use of bigger scale industies through integrating small scale ones. In addition, energy price adjustment, promotion of technology and inflation rate control, as the permanent policies to decrease energy intensity, could be effective.