Abstract: A method for the direct detection of essential oil in tea tree plumule is proposed in the resent article. The method was based on an apparatus that combines ideally thermal desorption with GC/MS. The plant essential oil can be monitored directly without complex sample pretreatment. Parameters of the thermal desorption were optimized. The thermal desorption temperature program started with a 15oC/min ramp from 40 oC to 150 oC and then maintained 3 min. The total desorption time was 11min. The component content would be effected usually from different sampling position. The method has good reproducibility. RSD value of terpineol-4 was 1.61. The proposed method is rapid, feasible and efficient for the identification of the quality of the tea tree plumule.