PURPOSE: To obtain a patching agent of high skin adhesivity, sweat-resistant adhesivity and pharmacological effectiveness, along with good storage stability, by incorporating a specific block copolymer with aromatic hydrocarbon solvent, tackifying component and pharmacologically active ingredient.

CONSTITUTION: The objective patching agent can be obtained by incorporating (A) 100pts.wt. of an A-B-A type thermoplastic block copolymer constituted by (1) rigid polymer A with a glass transition temperature Tg ≥70°C and weight- average molecular weight Mw 1,000W50,000 (e.g. polystyrene) and (2) flexible polymer B with a Tg -100W30°C and Mw 4,500W1,000,000 (e.g. polybutadiene) with (B) 5W150pts.wt. of an aromatic hydrocarbon with a boiling point 150W 400°C and viscosity 5W500cps, (C) 10W400pts.wt. of a tackifying component (e.g. resin), and (D) pref. 0.1W30wt%, based on the adhesive base made up of the components (A), (B) plus (C), of a pharmacologically active ingredient. This patching agent in then provided on a substrate.