PROBLEM TO BE SOLVED: To provide a viscous composition showing extremely high thickening properties even when only a small amount of it is added, and a thickener comprising the same.SOLUTION: The present invention provides a viscous composition comprising an alkyl-modified carboxyl group-containing water-soluble polymer and a polyalkylene oxide modified product, and a thickener comprising the same.SELECTED DRAWING: NoneCOPYRIGHT: (C)2016,JPO&INPIT【課題】少量の添加でも極めて高い増粘性を示す粘性組成物及びこれを含有してなる増粘剤を提供すること。【解決手段】アルキル変性カルボキシル基含有水溶性重合体とポリアルキレンオキシド変成物を含有する粘性組成物、及びこれを含有してなる増粘剤。【選択図】なし