Abstract: This paper shows the chemical constituents of the essential oils from the leaves of Cinnamoum pauciflorum Nees. By applying the techniques of fractional distillation, column chromatography, TlC, GC and IR, the following 13 components have been separated and identified: three monoterpenes–α–pinene (1.28%), camphene (0.17%), and p-cymenc (0.14%); five oxygenated monoterpenes–1,8-cineole (0.85%), lina-lool (14.35%), α-terpineol (0.22%), safrole (69.70%) and eugenol (4.20%), two aldehyde compoundes–nonyladehyde (0.16%) and decytadehyde (0.40%); two sesquiter–pene–β–caryophyllene (0.11%) and β–bisabolene (0.05%); one oxygenated sesquiter–pene-nerolidol (0.75%). In addition, the variations of the content of the major components of tile oils in various months have been determined.