The foundation of a building is the subgrade. Based on its physical and mechanical properties, the soil serves as a load-bearing structure. The method used in this study is based on research tests done at the Material Testing Laboratory of the Public Works Department of East Nusa Tenggara Province. The soil mechanical properties test looks at the California Bearing Ratio (CBR), the Strength Unconfined Compressive Strength, and the Shear Strength of Soils. The soil physical properties test looks at the grain size distribution, soil compaction, and moisture content. The results of the physical tests on the soil showed that the soil with the lowest gradation rate was 51.44 % and the soil with the highest gradation rate was 95.72 %. Based on the water test, the lowest value was 23, which was 2.73 Ton/M3. The land in this area has a sandy top cover or sandy top soil. At the bottom, there is white silt soil and clay content, which makes it a regosal type of soil. This soil has general characteristics on the surface, such as coarsetextured sand with low bearing capacity. Physical testing of gradation figures for the lowest soil was 51.44 % and the highest was 95.72 %. Based on the specific gravity test, the value of Soil Density was 2.72 Ton/m3.

Subgrade, Physical, Mechanical Properties, CBR, Unconfined Compressive Strength, Shear Strength of Soils.