PURPOSE: To obtain a ground having better water-hold efficiency easily and inexpensively by piling up water-holders provided with standing water holding sections inside of them and equipped with through-holes up and down in a multistage way under the ground, and covering the upper surface of them with the ground soil.

CONSTITUTION: In an area having a high permeable ground such as a desert and the like, water-holders 1 (used tires for automobiles) are piled up in a state of lying down in a multistage way under the ground. An impervious sheet 2 is laid on the bottom, if necessary. The upper surface of the water-holders is covered with the ground soil 3, and the dryness of the ground soil is prevented by standing water in the used tires. According to the constitution, a ground having better water-hold efficiency can be easily obtained at a low cost.