Here is disclosed a disposable pull-on wearing article improved so that a body fluid absorbent core may be curved about a crotch region toward front and rear waist regions without forming thick creases creating a feeling of discomfort against a wearer, and wherein a concavity bulging downward may be quickly formed in the crotch region as the core is curved. The article includes a body fluid absorbent core which includes a first core lying on a transverse middle of a crotch region and a pair of second cores lying on both sides of the first core. Front and rear end portions of the respective second cores are spaced apart from the first core by slit-like gaps and intermediate portions extending between the front and rear end portions are contiguous to the first core. Outer side edges of the respective second cores are formed with laid down V-shape cutouts.