A fluidized sand composition for use as a filling material for sinkholes and the like weakened ground cavities. The fluidized sand composition is produced by mixing graded sand, water, a fluidizer, a plasticizer, and a surface active agent. The fluidized sand composition is easily injected into the ground cavity of a sinkhole. After filling, the fluidized sand composition will return to the solid natural condition according to the effect of plasticizer previously added. The fluidized sand composition allows for compaction, soil stabilization, permits water migration through the material, and can be easily excavated.