A lamp base assembly with electronic ballast for energy-saving lamp includes a housing (22), a lamp cap (21) and an electronic ballast (24) with transistors (23) provided within the housing. A transistor heat-diffusing element surrounding each transistor is provided within the lamp base, for enhancing the heat transfer from the transistors to the housing or the lamp cap, so that the heat generated from the transistors could be transferred out of the lamp base assembly. Thus, the heat-diffusing ability of the transistors is improved, and the working temperature of the transistors could be kept within a safe scope, so that the lifetime of the energy-saving lamp is guaranteed.