<p>An emulsified alkenylsuccinic acid sizing agent having a solid content of not less than 25 % by weight is disclosed, which comprises a composition having not less than 25 parts by weight of alkenylsuccinic acid derived from reaction product of a branched internal olefin of 12 - 18 carbon atoms with maleic anhydride, and being dispersed in water with an anionic polymer type dispersant or with an anioic polymer type dispersant and an emulsifier.</p>
