PROBLEM TO BE SOLVED: To provide a gelatinizer which can provide a gelatinous composition such as a solvent and an oily agent with highly thixotropic viscosity, and a highly thixotropic viscous composition. SOLUTION: The gelatinizer comprises a starch benzoic acid ester having a specific substitution degree and an amylose content of less than 5%. The cosmetics, the drugs, the quasidrugs, the paints and the inks comprise the highly thixotropic viscous composition obtained by dissolving the gelatinizer. The highly thixotropic viscous composition is excellent in spreadability and adhesiveness, and is an excellent base material for cosmetics, drugs, quasidrugs, paints and inks.
