Soft soil (ground) which consists of clay or silt is a ground that can make big problems to stability and subsidence of structure owing to higher groundwater level, saturation and bearing power. Ground improvement means that improvement of soil’s engineering property and increase the stability. Deep Cement mixing is a representatively ground improvement method. DCM method is that while injecting solidification materials that mixed cement with water into the excavated hole, building a grout-mix column through augering. DCM method is applicable to onshore and offshore. Dong-Ah has many records to onshore and offshore in the Korea. Moreover, we are doing business in the Singapore, Vietnam, Myanmar, and Hong-kong with high technical skills.