A heat dissipating design for lamp is disclosed. The heat dissipating design of the present invention comprises a main body, which includes a cover. The cover seals up the top portion of the heat dissipating unit, and hence a sealed space is formed. A plurality of light generating units, a light generating units plate, an AC/DC adopter unit and one or more heat conducting pieces are disposed in the sealed space. When heat is generated by the light generating units and the AC/DC adopter unit, heat is transferred to the light generating units plate and the heat conducting pieces and then to the heat dissipating unit and the heat dissipating pieces. Heat is then dissipated into the ambient air. In this way, heat may be dissipated quickly and efficiently.