A wetness indicator composition contains (a) 0.1% to 5% by weight of a pH indicator that is substantially colorless at pH 7 and develops a color in an acidic environment, (b) 20% to 90% by weight of a surfactant, (c) 5% to 55% by weight of a polyalkylene glycol, (d) 0% to 70% by weight of a polymer having a carboxyl group, and (e) 0.1% to 5% by weight of an acidic substance other than components (b) and (d). In an absorbent article including a topsheet 2, a backsheet 3, and an absorbent member 4 interposed between the topsheet 2 and the backsheet 3 and having applied thereon a hot-melt composition that changes color on contact with a body fluid, the wetness indicator composition is used as the hot melt composition.