Abstract: The aim of the present study was to assess the effect of different extraction conditions on production of lemongrass essential oil, and to determine the optimal ratio of solid to liquid and mass concentration of Na Cl. Steam distillation method was used to extract essential oil from lemongrass produced in Hainan Province; there were four levels for both ratio of solid to liquid（1∶5, 1∶10, 1∶15, 1∶20） and mass concentration of Na Cl（3 g/L, 6 g/L, 9 g/L, 12 g/L） and there were three replicates for each level;the optimal ratio of solid to liquid was initially determined by single factor experimental design using yield of lemongrass essential oil as assessment index, and subsequently the optimal mass concentration of Na Cl was screened. The results showed that the optimal extraction process of essential oil from lemongrass produced in Hainan Province by steam distillation was as follows： the extraction duration was three hours, the ratio of solid to liquid was 1∶10, and the mass concentration of Na Cl was 9 g/L. Under this condition, the maximum yield of oil（0.68%） was obtained.