A pull-on absorbent article (1) includes a front panel (2A), a rear panel (2B), and an absorbent assembly (3) fixed to them so as to bridge them. Each of the front panel (2A) and the rear panel (2B) includes a body portion (20a, 20b) including side seals (4) at both lateral sides and an extension portion (21a, 21b) extended toward a crotch section (C). The absorbent assembly (3) includes an absorbent member (33) and side sheet portions (34) located outward of both edges in the longitudinal direction of the absorbent member (33). The side sheet portion (34) includes a stretchable region (34c) having stretchability due to an elastic member (36) fixed in a stretched state at least at the crotch section (C). In the stretchable region (34c), a length Lm from the center line (CL) of the article to a front end part (34m) is larger than a length Lu from the center line (CL) to a rear end part (34u).褲型吸收性物品(1)具備腹側片材構件(2A)、背側片材構件(2B)及架設並固定於其等之上的吸收性本體(3)。腹側片材構件(2A)及背側片材構件(2B)包含左右兩側具有側封部(4)之本體部(20a、20b)及向下襠部(C)側延伸之延伸部(21a、21b)。吸收性本體(3)具有位於吸收體(33)及該吸收體(33)之長度方向之兩側緣各自之外側之側部片材部(34)。側部片材部(34)係於至少下襠部(C)具有藉由以伸長狀態固定之彈性構件(36)而顯示伸縮性之伸縮區域(34c)。伸縮區域(34c)中，自物品之中央線(CL)至腹側端部(34m)為止的長度Lm長於自該中央線(CL)至背側端部(34u)為止的長度Lu。
