The vapour pressure of water above an aqueous solution of sucrose at T = 298.06 K has been measured for 9 sucrose mole fractions up to 0.12. Vapour pressure measurements have also been made on aqueous solutions of meso-erythritol, xylitol, sorbitol, fructose, and raffinose at T = 317.99 K. The excess molar enthalpy has also been determined for the aqueous sucrose system at T = 318.15 K. The data obtained are compared to literature data for related systems and the effects of the solutes on solution structure are discussed.