In a battery pack structure for electric vehicles that a battery module, a junction box, and a battery controller for battery management are mounted in a battery-pack-case internal space, clearances, ensured when the battery module is mounted in the case internal space, are configured as temperature-adjustment air passages through which temperature-adjusting air flows. The junction box and the battery controller are arranged at positions spaced apart from each other and facing one straight passage part of the temperature-adjustment air passages. Furthermore, a weak-electric harness, via which the junction box and the battery controller are connected to each other, is wired along the straight passage part, thus ensuring smooth flow of temperature-adjusting air, while improving both the harness-wiring workability and the harness durability.