Patented is an absorbent article having a liquid retentive absorbent layer and a liquid impermeable leak preventive laye. The article includes, in its longitudinal direction, an excretion portion which is placed opposite a wearer’s liquid excretion portion and a rear section which is placed more on the back side than the excretion portion, wherein a leak preventive wall is disposed on opposite side portions in the longitudinal direction. The leak preventive wall has a basal wall portion and a planar elastic expansible/contractible portion connected to an upper end portion of the basal wall portion and raised in the excretion portion and in the rear section, and wherein a distance from an upper end portion of the basal wall portion to the leak preventive layer in the rear section is shorter than a comparable distance in the excretion portion.