Abstract:The leaves of 3- to 5-year-old ginkgo (Ginkgo biloba) were collected from Pixian County in Jiangsu Province in September, and a yellow essential oil was obtained by water distillation. Forty-four compounds from the essential oil were determined by GC and GC-MS, which consisted of 31 .14% hydrocarbons, 5.61 % alcohols, 1.78% aldehydes, 46.17% ketones, 5.41 % acids and 1.1% esters. In ketones of the oil, the content of hexahydrofarnesyl acetone was found highest (11.15%), followed by nerylacetone (8.68%), β-ionone and farnesyl acetone, amounting to 5.24% and 3.73%, respectively.