Abstract: Thermopsis laceolata R. Brown was reported that ten alkaloids were isolated from this plant, including three groups of quinolizidine: (1) the anagyrine type; (2) the sparteine type; (3) the lupanine type. Biological activities of five quinolizidine alkaloids from the plant have been studied, the result showed that they have physiological and pharmacological activities to bacterium, insect, nematode and mammal animal. The alkaloids from the plant can cause muscle relaxation, blood pressure reduction and slow down rhythm of the heart.