NOVELTY - The structure has two battery modules (22, 23) which are arranged in the vehicle front area of an internal space of battery pack case (1), having dimension set lower than the height dimensions of a battery module (21). Heat regulation unit includes a ventilation duct (9) for ventilating a heat regulation wind with respect to battery modules. An air blowing opening of fan duct through which heat regulation wind is blown towards the vehicle rear is formed at other end position, and extends in the vehicle width direction along module front surface upper area.    USE - Battery pack heat regulation structure of electric vehicle such as sedan type electric vehicle, trolley type electric vehicle and sport utility vehicle (SUV) type electric vehicle. Can also be used in propulsion motor and hybrid electric vehicle.    ADVANTAGE - Since the heat regulation wind from the heat regulation unit can pass through the fan duct from ventilation duct, the wind can be blow off from blowing opening of the fan duct towards the vehicle rear surface. The one end of ventilation duct facing the upper area of module front surface of battery module, so that the temperature of the battery module can be fallen, when cooling air is previously blown off with respect to the battery module and the atmospheric temperature of the interior space of a battery pack case can be reduced. Thus the battery module can eb cooled. The temperature head of the battery modules can be suppressed in short time, and temperature uniformization of the battery module can be attained efficiently. The blowing opening of the fan duct can be opposingly arranged in the module front top area of the battery module, so that the need for making height of the fan duct higher than the height of battery module, and the largest height dimension of the battery pack case can be decided, without considering the height of fan duct. The largest height of the battery pack case can be restrained low. Thus the temperature uniformization of the battery module accommodated in battery pack case can be attained.    DETAILED DESCRIPTION - The one end of ventilation duct is connected to a ventilation port in heat regulation unit and other end facing the upper area of module front surface of battery module (21).    DESCRIPTION OF DRAWING(S) - The drawing shows a top view of the internal structure of battery pack.    Battery pack case (1)    Ventilation duct (9)    Battery modules (21,22,23)    Cyclic channel (38)    Duct portion (93)