A power control unit for electric vehicle which can easily detach the high voltage cables even if the motor room is deformed, for example, by head-on collision and/or rear-end collision of the vehicle, which is difficult to be deformed, which can make small, and which can avoid an influence of heat generated by the reactor is disclosed. The power control unit 1 includes a box 10 which accommodates devices for controlling electric power supply of the electric vehicle; a reactor receiver 11a which is provided on a given external surface around the box 10 and supports a reactor R; a heat sink 12 connected to the lower end of the reactor receiver 11a, covering the bottom surface of the box 10, possessing passages including passage wall inside thereof, and performing heat-exchange with the box 10 by allowing coolant water to flow within the passage; and a partition 13a, which is laid on at least one side of the box 10 extending toward the longitudinal direction of the vehicle EV, and is detachably communicated with cables to be connected to the traction motor 4 disposed below the heat sink 12 to supply power.