The present invention has objects for providing a method for inhibiting the moisture variation in compositions, a composition whose moisture variation is inhibited, and an agent for inhibiting the moisture variation in compositions. The objects are solved by providing a method for inhibiting the moisture variation in compositions comprising incorporating into a composition a saccharide-derivative(s) of .alpha.,.alpha.-trehalose as an effective ingredient, a composition whose moisture variation is inhibited by incorporating the saccharide-derivative(s), a moisture variation inhibiting agent containing the saccharide-derivative(s) as an effective ingredient, and uses thereof.