The components of the essential oils obtained from different parts of Daucus carota L. var. sativa Hoffm were analyzed. The percentages of the essential oils extracted are 0.27%(mL/100 g material) for the flowers, 0.07% for the stems and leaves and 0.01% for the roots. Fifty-four, Sixty-six and Thirty-three compounds were,respectively,separated and identified from the flowers, the stems and leaves and the roots, among which unsaturated alkene compounds are thirty-nine, thirty-nine and twenty-one, respectively, accounting in turn for up to 90.21%, 90.49% and 72.65% of the total essential oils. Because alkene compounds have double bonds that are easily oxidized, it can be inferred that the components of the essential oils in the different parts of Daucus carota L. var. sativa Hoffm should show an activity of the anti-formation of free radicals to some extent.