Seeds of cedro (Cedrela fissilis) were accelerated ageing under temperatures of 40 or 50oC, in an ageing chamber, for 24, 48, 72 and 96 hours. Germination changes in carbohydrate (CAD) and lipid contents, and membrane permeability were evaluated. At temperature of 40oC there were no major changes in carbohydrate, lipid, exudate and germination percentages. Nevertheless, at temperature of 50oC carbohydrate content and germination percentage decreased and membrane permeability significantly increased. Lipid content slightly decreased.