AbstractHedysarum laeve (Fabaceae) is an important legume for plant ecosystem restoration and reconstruction in Mu Us Sandland, Inner Mongolia. Fruit set is greatly enhanced when pollinators are available in the H. laeve system, since fruit set is stimulated less by spontaneous autogamy. This species is pollinated mainly by wild bees, but there is insufficient information to determine the overall effectiveness or importance of the pollinators. We investigated the composition of bee pollinator species of H. laeve and the pollination efficiency of the dominant ones. The species and numbers of pollinators of H. laeve were investigated in four 2 m×2 m plots in Mu Us Sandland during 2004–2006. We observed visitation frequency of the main pollinators and measured their pollen removal ratio from anthers after a single visit to virgin flowers, pollen deposition on stigmas by a single visit to virgin flowers, and the duration of each visit. The results showed that three bees Anthophora albifronella, Megachile maritima and Bombus sporsdicus were major pollinators, of which A. albifronella was dominant in number and visitation frequency. A. albifronella removed less pollen than M. maritima and B. sporsdicus, but the three bee species deposited similar amounts of pollen on stigmas. We suggest that A. albifronella was the most efficient pollinator for H. laeve according to comparison among the three bees of the amount of pollen removal, the pollen deposition on stigmas, and visitation frequency.