PROBLEM TO BE SOLVED: To provide a UV-LED light hardenable ink composition for ink jet printing which has good discharge stability at ordinary temperature for an ink head designed to allow use of a low-viscosity ink intended for energy saving and high speed and high definition requirements and is also excellent in UV-LED light hardenability, friction resistance after hardening and adhesion to a substrate.SOLUTION: A UV-LED light hardenable ink composition for ink jet printing comprising a photopolymerizable compound, a photopolymerization initiator and a surfactant contains 55-80 mass% of vinyloxyethoxyethyl acrylate and 2.5-20 mass% of a tri- and/or tetra-functional (meth)acrylate monomer as photopolymerizable compounds and 5-20 mass% of an acyl phosphine oxide type photoinitiator as a photoinitiator and has a flash point of 70°C or higher, measured by a method based on JIS K2265 by using a Seta closed-type flash point measuring instrument, and a viscosity at 25°C of 12 mPa s or lower.
