The adhesive composition for soft tissues, the adhesive composition for wound dressing or the wound dressing agent composition of the present invention is an adhesive composition for soft tissues, an adhesive composition for wound dressing or a wound dressing agent composition, comprising a monomer (A), a polymer (B) and a polymerization initiator composition (C) containing an organoboron compound, and is characterized by having a viscosity of 0.4 to 75,000 cp within 30 seconds after mixing of the components (A), (B) and (C). The composition of the present invention not only has low toxicity, low harmfulness and high adhesive strength but also is excellent in workability during application and is capable of forming films of excellent properties.