To provide an integrally formed composite structure excellent in lightweight properties and water permeability, and a method for manufacturing the same.

The composite structure comprises a plurality of concrete demarcated parts containing granular or fragmentay aggregate comprising waste plastics such as foamable polystyrene or the like and cement and demarcated by grooves and the water permeable layer formed under the concrete demarcated parts and comprising a rubber chip aggregate. In order to hold the mutual strength of the concrete demarcated parts in a lateral direction, a reticulated reinforcing material can be embedded in the concrete demarcated parts. In order to enhance water permeability, slits may be formed to the grooves of the concrete demarcated parts up to the water permeable layer, By utilizing the lightness of the composite structure, the laying work of the composite structure to the veranda and rooftop of a house or mansion, a park or the like can be efficiently advanced.