The construction waste concrete produce from the demolished concrete structures. These waste concrete materials are useful and valuable for fill and subgrade and are considered to use as the subgrade material of the road. To use the subgrade of the road with the waste concrete, the several experiments involved with compaction test and laboratory C. B. R. etc. are performed. These experiments are compared with criteria of the road construction manual. It is shown that the quality of the construction waste concrete satisfies that of the subgrade mentioned in the road construction manual.