Equilibrium conditions of clathrate hydrates formed from xenon and aqueous solutions of dimethyl sulfoxide (DMSO), formamide, acetamide, isobutylamine and pyrrolidine were experimentally measured up to 1.0 MPa using an isochoric method. Adding DMSO, formamide and acetamide shifted the xenon hydrate equilibria toward low temperature, indicating that these additives acted as thermodynamic hydrate inhibitors. The inhibiting effects of the additives were almost as strong as those of methanol and ethylene glycol on a mole basis. In contrast, isobutylamine and pyrrolidine had promoting effects on xenon hydrate formation. The promoting effects were stronger than that of acetone but weaker than that of 1,3-dioxolane. (C) 2019 Elsevier B.V. All rights reserved.