An intercooler assembly includes: a cooler body having a heat exchanger; an upper tank formed at an intake air inlet connected to the heat exchanger and coupled to an upper portion of the cooler body; a lower tank coupled to the lower portion of the cooler body to form an intake air discharge part connected to the heat exchanger; a bypass unit connected to the intake discharge part separately from the intake inlet; and a valve unit connected to the intake air inlet and the bypass unit and selectively introducing intake air supplied through a turbocharger into the intake air inlet and the bypass unit.