A self-assembly coating material including carbon particles and polymer shells is provided. The polymer shells respectively cover and are bonded to the carbon particles, wherein each polymer shell has both a first functional group for adsorbing on a surface of a substrate and a second functional group for self cross-linking. The first functional groups include thiol groups. The second functional groups include epoxy groups or carboxylic groups. The self-assembly coating material can be applied to a metal substrate to form a heat dissipation layer.