A pull-on disposable diaper (1A) of the present invention includes a pair of side-sealing sections (8, 8) each being formed by fusion-bonding of respective overlapped sections (7, 7) where opposite side-edge sections (6a, 6a) of a stomach-side section (A) and opposite side-edge sections (6b, 6b) of a back-side section (B) overlap one another. In the pull-on disposable diaper (1A), each of the side-sealing sections (8, 8) includes regions each having a different total basis weight of members that make up each overlapped section (7). Each overlapped section (7) of the pull-on disposable diaper (1A) is made up of a plurality of members. The larger the total basis weight of the respective basis weights of the plurality of the members is in a region of the side-sealing section (8), the smaller the fusion-bonded area is made in that region of the side-sealing section (8).
