Abstract: In this study,the essential oils were extracted from both fresh and dry flowers of two cultivars of Yunnan Lavandula spp.(CAS07 and CAS08) using steam distillation method. The chemical constituents were analyzed using GC-MS,and their contents were determined by peak area normalization method.The results showed that the yields of fresh and dry flowers of CAS07 were 2.2% and 2.7%,respectively,while the yields of fresh and dry flowers of CAS08 were 3.3% and 3.8%,respectively.A significant difference (P<0.01) was observed in the yields of two cultivars but the difference was not significant (P>0.05) between the fresh and dry flowers within the same cultivar.Moreover,the principal constituents of the essential oil extracted from CAS07 were linalool (38.6%-39.2%),linalool acetate (21.80%-26.71%) and lavandulol acetate (7.69%-13.15%).The essential oil of CAS08 extract maily included eucalyptol (49.70%-49.80%),camphor (13.6%-14.3%) and α-bisabolol (6.6%-7.7%).We found that the yields and qualities of oils which extracted from fresh flowers were higher than dried flowers.The results of this study can provide a theoretical basis for Yunnan Lavandula spp.Industry policy,and a reference for the construction of the ecological park and beautiful family farms.

Key words: Lavandula spp., essential oil, linalool, linalool acetate, eucalyptol