Objective: To study the optimal methyl esterification method in alkali alcohol eluent from Yiqi Fumai lyophilized injection. Method: Some esterification methods were adopted as follows:1% sulfuric acid-methanol refluxed esterification method

10% sulfuric acid-methanol refluxed esterification method

25% sulfuric acid-methanol refluxed esterification method and 2% potassium hydroxide-methanol refluxed esterification method. The solution of methyl esterextraction was extracted by opportune solvent

then

analysis them with GC-MS. Result: 10% sulfuric acid-methanol refluxed esterification with extracted by chloroform is the optical method

which shows the best esterification efficiency. Conclusion: 10% sulfuric acid-methanol refluxed esterification is the best esterification method of alkali alcohol eluent from Yiqi Fumai lyophilized injection

which provides the basis for the research on the main ingredients of this extract.