The invention discloses a green roof structure with the rainwater retaining ability. The green roof structure comprises a plant layer, a soil layer, a filtering layer, a water storage and drainage layer, a moisture preservation layer and a waterproof layer from top to bottom; the plant layer is composed of perennial herbs, namely sedum lineare, the planting row spacing is 4-6 cm, and the line spacing is 8-10 cm; the soil layer is composed of mixtures of light sandy soil, humus and vermiculite, and the thickness of the soil layer is 15-20 cm; the filtering layer is composed of polyester fiber non-woven fabrics and extends towards the side wall surface of a building to the part below surface soil by 5 cm, and the effective width of lap seams is 10-20 cm in the laying process; the water storage and drainage layer is composed of polyethylene concave-convex drainage boards with the thickness ranging from 30 mm to 60 mm; the moisture preservation layer is composed of moisture preservation blankets with the thickness ranging from 20 cm to 30 cm, and the moisture preservation blankets are arranged adjacently and closely; the waterproof layer is composed of polymer modified asphalt root-resisting waterproofing membranes. The green roof structure has the advantages that the land resources are saved, the green area is increased, the environment is beautified, the heat island effect is reduced, the storm runoff is lowered, and the air pollution is reduced.