This research is to study the bearing capacity of the cement treated soil admixed with air foam for applying as fill material. The lightweight embankment with 4 meters length, 4 meters wide and 1.5 meters high was instrumented. Accordind to ASTM D1194, Plate Bearing Test was conducted using 3.5 tons of dead load. Moreover, the relationship between loads and settlements was illustrated. Thereafter, the samples of soil around the embankment area were collected to find the strength parameters for analyzing and comparing with the finite element method (FEM). The results of the bearing capacity of the cement treated soil admixed with air form study are first, the steel plate that used for testing has settlement to 20 and 21 millimeter. Second, the maximum bearing capacity is equal to 44 tons per square meter. Finally, the ultimate strength is equal to 23 and 24 tons per square meter. The comparison between the result that uses finite elements method and result from the field shows that both of them have the same direction