Objective : To study the chemical constituents from pine needle of Pinus crassicorticea and P. yunnanensis Franch.var tenuifolia. Method :The essential oils from Pinus crassicorticea and P. yunnanensis Franch.var tenuifolia were extracted by steam distillation. The volatile components were analyzed by gas chromatography-mass spectrometry (GC-MS) methods. The relative contents of these constituents were calculated by peak area normalization. Result : Sixty two compounds in the essential oil from P. crassicorticea were identified

counting for 95.565% of the total area of the peaks. The principal constituents were α-pinene (24.659%)

β-pinene (11.471%)

β-caryophyllene (9.932%) and terpinolene(5.167%). 55 compounds in the essential oil from P. yunnanensis Franch.var tenuifolia were identified

counting for 90.794% of the total area of the peaks. The principal constituents were α-pinene (22.542%)、β-caryophyllene (16.636%) and 1

2

4a

5

8

8a-hexahydro-4

7-dimethyl-1-(1-methylethyl)- naphthalene (5.085%). Conclusion :The essential oils from pine needle of P. crassicorticea and P. yunnanensis Franch.var tenuifolia were investigated for the first time.It had provided scientific foundation for exploitation and utilization of P. crassicorticea and P. yunnanensis Franch.var tenuifolia.