(Problem) Providing an ink composition, particularly an ink composition for use in inkjet recording, which can form an image with good adhesion and high quality and which is excellent in storage stability, and an inkjet recording method and a printed matter using it, as well as a lithographic plate which can record an image with no blot, high sensitivity and high adhesion to a recording medium and a method for making such plate. (Solving Means) The foregoing problem may be achieved by an ink composition comprising: (a) A cationically polymerizable compound; (b) a compound generating an acid by irradiation of radiant ray; and (c) plasticizer, particularly at least one ester compound selected from the group consisting of phosphate ester, dicarboxylic acid ester and tricarboxylic acid ester.