The aim of this research is to study the effect of compaction energy on Jerash cohesive soil. Qualitative and quantitative analyses of soil compaction energy with relation to unit weight and moisture content are conducted. These analyses spot the light on energy savings performed for soil compaction. The study shows that as the compaction energy increases; the unit weight of the Jerash cohesive soil increases and the optimum water content decreases. Generally, a soil with low moisture content is less vulnerable to compaction than a soil with high moisture content. But when the moisture content is too high, all the soil pores are filled with water, so that the soil becomes less compressible where the unit weight and strength characteristics decrease. The optimum energy value and optimum water content are thus of great concern. The effect of energy on soil unit weight is very large as the energy increases from 400 to 1400 KJ/m 3 and after that level; the effect of energy on soil unit weight is very small. Consequently, optimal compaction energy ranges from 1200 up to value 1400 KJ/m 3 , where 50 to 60 blows can be applied and the optimal correlated water content is between 14% -15%.