Three lectins have been isolated from leaves of Aloe vera L.ver.chinensis(Haw), Aloe barbadensis Mill and Aloe arborescens Mill which have pharmic value by gel filtration: Lec1, Lec2, Lec3. The main components and content of three lectins were analyzed. In vitro assays for immunological tests, the lectin from Aloe barbadensis Mill has the highest hemagglutinating activity. All of them have the ability of markedly promoting the lymphocyte transformation. Therefore they have the applicable prospec...