Abstract: At 250,300,400,500,600,700,800 and 900℃,the pyrolysis products of cinnamon leaf oil were analyzed by gas chromatography/mass spectrometry,and the relative content of the pyrolysis products were also calculated by normalization method.The results indicated that:1)cinnamon leaf oil was not pyrolysised at 250℃,and released out of flavor substances,such as eugenol,β-caryophyllene and aceteugenol;2)under 600℃,52 pyrolysis products were released from the essence;3)above 700℃,no flavor was found in the pyrolysis products.Furthermore,with the raise of pyrolysis temperature,harmful substances were released,such as aromatic,polycyclic aromatic hydrocarbons;and the category and relative content of them increased with the temperature;4)the pyrolysis products of cinnamon leaf oil were mainly possible came from eugenol.