This research focused on the potential utilization of cement waste (CW) as a stabilizer to improve the compressive strength of clay soil. .A series of laboratory compaction and CBR tests were carried out. Soil specimens were compacted at maximum dry density with different percentages of cement waste 3%, 6%, 9%, 12% and 15% of weight of clay soil). Results indicate that an increasing of cement waste content decreases the maximum dry density and the optimum moisture content (OMC). Soil became non plastic when the addition of cement waste content was equal to or greater than 9% of weight of clay soil. An increasing of cement waste content increased the CBR values of clay soil and the highest value was 8.3 times the CBR of non treated soil and it was achieved at 9% of cement waste.