A thickening composition characterized by containing xanthan gum having per 100 parts by weight thereof, 0.5 part by weight or more of metal salt bound on the surface of xanthan gum powder. This thickening composition is capable of convenient viscosity development by addition to water-containing objects. Thus, the thickening composition is suitable for use in, for example, food application for convenient thickening of soft drink, basting, sauce, dressing, soup, mousse, jelly, etc., or application for viscosity development by addition of a small amount thereof to meals for patients having difficulty in mastication/swallowing due to eating disorder, etc.