The purpose of the research was to optimize the carbon source, initial pH of the microorganism Acinetobacter junii.5-6 fermentation medium.At last these trace elements including K2HPO4、NaH2PO4、FeSO4.7H2O、NaMoO4、MgSO4.7H2O、and CaCl2 were respectively added into the most suitable medium,each kind of trace elements was 1g/L,the best was K2HPO4 .However, the concentration of bacteria was not significantly improved, and the higher cost.So trace elements were not considered to add in the subsequent fermentation. Ultimately the optimal initial pH determined was 5.5.Optimal medium composition was Sunflower oil 2% (v / v), molasses 0.2% (m / v), NaCl 5g / L, NaNO3 10g / L and beef extract 5g / L.