Disclosed is a cooling system for a fuel cell vehicle which employs a single integrated radiator disposed on a front side of the vehicle and configured to cool cooling fluid by exchanging heat using exterior air to integrally manage a fuel cell stack and an electrical power apparatus. More specifically, the integrated radiator is divided into a first high temperature region and a second low temperature region according to a flow requirements so that the fuel cell stack is cooled with cooling fluid flowing through the high temperature region and the electrical power apparatus is cooled with cooling fluid flowing through the low temperature region.