Headspace GC method was established for the determination of propanol in erythromycin fermentation liquid,the method is stable and  accurate,the liner range is 2×10-5～1.2×10-3, r = 0.999 5, the limit of quantification is 2×10-5, and the detection limit is 1×10-5. It can be used to guide the addition of propanol in erythromycin fermentation liquid, thereby improving the level of fermentation production.