A battery assembly mounting structure for a vehicle includes: a through pipe provided in a battery assembly such that a space vertically passing through the battery assembly is formed in an inner portion of the battery assembly, a swappable assembly coupled to an inner portion of the through pipe by an elastic force, and a fastening bolt which passes through an inner portion of the swappable assembly and is coupled to a vehicle body positioned at an upper side of the fastening bolt such that a fastening pressure is applied to a lower end of the through pipe.