PURPOSE: To provide a fuel cooling device which dispenses with consideration to the refrigerant pressure of an air conditioning cycle and consideration to the refrigerant leakage, when a fuel pipe is cooled by utilizing the refrigerant of the air conditioning cycle.

CONSTITUTION: This fuel cooling device is provided with a pipe cooler 18 mounted outside a fuel pipe 20, a pump 19 feeding fuel cooling liquid to the pipe cooler 18, and a heat exchanger 13 exchanging heat between the fuel cooling liquid and the refrigerant in the air conditioning cycle of an air conditioner for vehicle. In the heat exchanger 13, a pipe line 15 letting flow the refrigerant in the air conditioning cycle and a pipe line 16 letting flow the fuel cooling liquid are arranged through fins, and heat of the refrigerant of the air conditioning cycle is transmitted to the fuel cooling liquid through the fins so as to cool the fuel cooling liquid. The cooled fuel cooling liquid cools the fuel pipe 20 at passing through the pipe cooler 18, and hence vaporization of fuel in the fuel pipe can be prevented.