To solve a problem of insufficiency of waste disposal sites and environmental problems by reclaiming excavated soil (construction surplus soil) and concrete lumps and asphalt lumps of construction waste as an upper base course material of a road.

The concrete lump or asphalt lump of the construction waste, or a mixture of the concrete lumps and asphalt lumps, is added into the excavated soil and crushed, and calcined lime is added thereto and sieved into grains with grain diameters of 40-20 mm, 20-2.5 mm and 2.5-0 mm, which are mixed at a predetermined ratio, and then water is injected to adjust the water content so as to be reclaimed as the upper base course material.