The present investigation was conducted in Faculty of Agric . Ain Shams Univ.In Shubra EL- Khama Kaluabia Govemorate Egypt, to study three concentrations 0, 100 and 150 ppm manganese chloride and 0, 50 and 100 ppm Fe EDTA as foriar spray on Ambrosia mantime L plant during the two successive season 1997 and 1998 . The results showed a significant increase in plant height, number of branches , fresh and dry weight per plant and per plot as well as ambrosin and demisin in mg/100g leaves by foliar spray of high levels 150 ppm manganese and 100 ppm Fe in the two season.