Abstract: The influences of the branches maturity,the hot air drying and material status on the chemical compositions of Melaleuca ahemifolia oil were studied by GC-MS. The results showed that the contents of olefinic alcohol in essential oil extracted from immature leaves of Melaleuca ahemifolia was higher than that in old leaves,and the contents of alkene was lower than that in old leaves. After the material was dried by hot air,the contents of terpineol-4-ol in essential was reduced,the contents of 1,8-cineole was increased,and the other components had no obvious changes. After the material fermentation,the contents of enols decreased,the content of alkenes and 1,8-eucalyptol increased. Therefore,in order to obtain high-quality essential oil in the progress of processing leaves of Melaleuca alternifolia,it was necessary to grasp the harvest time according to the growth condition of branches. At the same time,the harvested materials were processed in time to avoid accumulation and fermentation. When the production capacity was small,the materials could be properly dried to prolong the processing time and relieve the production pressure.