${eta}$-Glucans are naturally occurring polysaccharides that are produced by bacteria, yeast, fungi, and many plants. Although their pharmacological activities, such as immunomodulatory, anti-infective and anti-cancer effects, have been well studied, it is still unclear how ${eta}$-glucans exert their activities. However, recent studies on the ${eta}$-glucans receptors shed some light on their mechanism of action. Since ${eta}$-glucans have large molecular weights, they must bind surface receptors to activate immune cells. In this review, we summarize the immunopharmacological activities and the potential receptors of ${eta}$-glucans in immune cells.