To provide an ink composition excellent in basic functions which are necessary as an ink composition such as pigment dispersibility, transparency, weather resistance and storing stability, especially, excellent in the adhesivity to a polyolefin resin film, moisture resistance, water resistance and heat resistance, and having little influence on the environment and human bodies; and to provide an ink prepared by using the composition.

An ink composition characterized in that an alkyl-acetalized polyvinyl alcohol resin having an average molecular weight of 100-800 and a hydroxyl group content of 15-40 mol% is compounded with an alkoxyamine having a primary amine and no secondary amine in molecule, and nitrocellulose, or it is compounded with a copolymer of ethyleneimine and a (meth)acrylic alkyl ester, and/or an alkoxyaminosilane having a primary and a secondary amino group in molecule. Further, an ink characterized in that it is prepared by using the ink composition.