Disclosed is a polyisocyanate composition derived from an aliphatic diisocyanate monomer and an alcohol, which satisfies all the conditions below in a state not containing the aliphatic diisocyanate monomer and a solvent. 1) Isocyanurate trimer concentration: 55-95 mass % 2) Number ratio of allophanate groups derived from the alcohol to isocyanurate groups: 1-20% 3) Urethodione dimmer concentration: 2-25 mass % 4) Viscosity at 25.degree. C.: 150-800 mPas