An illumination device having enhanced thermal dissipating capacity is provided. The illumination device includes a heat sink, an LED module, a cover, an LED driver, and a lamp base. The LED module is disposed at one end of the heat sink. The cover covers the LED module. The LED driver is in connection with the LED module, and includes a circuit board and at least one electrical contact member disposed on the circuit board. The lamp base is connected to the other end of the heat sink, and comprises an insulating unit, a first electrode, a second electrode and at least one contact port. The contact port is arranged on the lateral interior of the insulating unit, so that the electrical contact member of the LED driver may establish electrical connection with the lamp base.