A power connector assembly is provided which comprises a plug connector and a mating receptacle connector. The plug connector includes an insulative plug housing having a plurality of passageways divided by division walls and a plurality of plug terminals accommodated in the corresponding passageways of the plug housing. The receptacle connector includes an insulative receptacle housing having a receiving space for receiving a part of the plug housing inserted therein and a plurality of receptacle terminals accommodated in the receptacle housing for mating with the plug terminals. Airflow channels are formed between the outer surface of the part of the plug housing in the receiving space and the inner surface of the receiving space for dissipation of heat.