The present invention relates to a wound dressing prepared by a hydrocolloid gel, a polyurethane film, a PVA hydrogel, an alginate gel or the like, which has excellent stretchability and exudation absorbency of the wound surface for protection and prevention of infection on the wound surface in which continuity of a body tissue is destroyed by a physical impact or the like, can maintain a wet environment suitable for promoting healing of the wound surface, and has no pain or no worry to damage regenerated skin when the wound dressing is exchanged.The wound dressing of the present invention is a composition for the prevention of infection on the attached surface of the wound dressing or on the wound surface. The wound dressing has a sterilization effect on staphylococcus aureus and the like and an effect on psoriasis and acne and uses a mixture of a methylene blue component used as a photosensitizer in photodynamic therapy for various skin diseases and an organic acid improving efficiently the photodynamic therapy effect of the methylene blue component as an active ingredient.
