A cooling method can be used with an electric vehicle that comprises a vehicle charging connection unit connected to an external cable connected to a charger located outside the electric vehicle, a battery configured to be charged through the vehicle charging connection unit, and a pump configured to circulate cooling water to cool the vehicle charging connection unit. The cooling method includes determining whether an amount of cooling water is insufficient and, upon determining that the amount of cooling water is insufficient, restricting a charging rate of charging power supplied through the vehicle charging connection unit.