A cooling structure of a battery pack includes an assembled battery including stacked battery modules, an intake passage, and a discharge passage. Ventilation passages extend between adjacent ones of the battery modules. The intake passage extends in a stacking direction of the battery modules and includes an intake port to draw in cooling air from a blower. The discharge passage extends in the stacking direction and includes a discharge port at a first end to discharge the cooling air, which flows through the ventilation passages, to the outside. The first end of the discharge passage and the intake port of the intake passage are located at the same side. The discharge passage is defined by a wall that includes a communication portion disposed at a position toward a second end of the discharge passage opposite to the first end to partially discharge air from the exhaust passage.