PROBLEM TO BE SOLVED: To provide a gelling agent having high gelling capacity so as to form a gel in a wide liquid range from acid to alkaline and further to form a gel in a small amount of addition even in the case of an aqueous solution dissolved with an inorganic salt and capable of imparting thixotropic properties by gels.SOLUTION: Provided is a gelling agent made of at least kind selected from alkylamide-D-glucamine and alkenyl amide-D-glucamine having a structure expressed by formula (1) (R1 denotes 9 to 23C fatty acid groups having 0 to 2 pieces of unsaturated bonds R2 and R3 respectively independently denote H or a 1 to 4C alkyl group capable of retaining H or C1 or 2 branch chains n denotes 1 to 10 and m denotes 1 to 2).SELECTED DRAWING: Figure 5COPYRIGHT: (C)2016,JPO&INPIT