This study was conducted by the tests of materials engineering and soil mechanics to see the strength characteristics of the ‘Cement-Mixed Soil'. To sum up my experiments, I would like to present the results which are the theoretical base and fundamental data to establish the standard design including the design of mixing proportions of the soil as a construction material. In conclusion, in this study the optimum cement mixing ratio is 9% and in this ratio the optimum moisture content of compaction work is 19.3% from the analysis of the strength characteristics, as well as in con-sideration of the economic profits and nature familiar facts.