A head lamp assembly including a housing; a plurality of head lamp cases installed in the housing, wherein each head lamp case comprises a light emitting diode (LED) light source, and a heat sink for dissipating heat generated from the LED light source; and a plurality of ventilating fans for circulating air in the plurality of head lamp cases and installed in the plurality of head lamp cases, respectively. Accordingly, the ventilating fans installed in the head lamp cases have opposite ventilating directions, and thus air is circulated in the head lamp cases by the ventilating fans to thus improve heat dissipation effects.