Abstract: The present invention discloses a cooling system with a passive heat dissipation structure, the cooling system includes plural heat conducting pipes, and a shielding tube included to surround the heat conducting pipes. The heat generated from a heat source placed below the cooling system heats the surrounding fluid (air) and turns it into heated fluid. The heated fluid is lower in density and is dissipated away through convection by the heat conducting pipes, leaves its original space to cooler fluid (at room temperature). The mixing of the heated fluid with the cooler fluid can be prevented by the heat conducting pipes, and the heat convection of the heat source by the cooler fluid is increased. With the implementation of the present invention, the benefits of easy implementing, easy to use, requiring no extra energy and saving costs are achieved, and the heat of the heat source is promptly dissipated away.