Metarhizium anisopliae, a microbiological pesticide, is widespread applied to control subterranean pests. Up to now, none reports on susceptibility of alfalfa leaf-cutting bee, an important pollinator of alfalfa and soybean, to M. anisopliae can be found. The alfalfa leaf-cutting bee infected by the fungus was studied. The results showed that mortality of prepupa and adults sprayed with M. anisopliae were over 50% in 4 days and 5days, 100% in 7.5 days and 10days, respectively. 100% of dead prepupa and 98 of dead adults produced spores of M. anisopliae. Alfalfa leaf-cutting bee is extremely susceptible to M. anisopliae.