This work was evaluated in the laboratory, the mechanical resistance under monotonic loads and the compression of several test bodies, by additions of lime and fly ash at 2%, 4%, 6% and 8%, based on the proctor test standard and the study soil (kaolin); prior to this, a characterization of the materials was made, and finally the objective was to determine the improvement of the soil through the comparisons, which refers to what is due to the best that is given to the best. Ash is not a significant improvement in the soil. In general, if a stabilization of a soil is required quickly, the data is published as a better option for soil improvement.