PROBLEM TO BE SOLVED: To provide a planting base structure requiring no water/electric facilities and having excellent improving effect on the thermal environment and preventive effect on urban flood. SOLUTION: This planting base structure comprises a planting layer for raising plant root system, a water-retaining layer set separating from the planting layer with space and composed of a material having a structure enabling homogeneously saving water retained by a capillary phenomenon, a porous body arranged so as to come into contact with the planting layer and the water- retaining layer and supplying water saved in the water-retaining layer to the planting layer, and a permeable root protection layer preventing root stems of plants from passing through the border of the planting layer and the space. COPYRIGHT: (C)2004,JPO
