Abstract: Homoharringtonine (HHRTN) was extracted from cephalotaxus sinesis ultrasonically for 40 min with ethanol (15 mL per 1 g of sample),and 3 extractions were necessary for each sample.Extracts were combined,evaporated under reduced pressured,made up to 10.0 mL and used for HPLC analysis.The Diamonsil C18 column was used as stationary phase in the chromatographic determination.A mixed solution of 0.08 mol·L-1 NH4OAc solution and methanol (mixed in the ratio of 55 to 45 by volume) was used as mobile phase.UV detection at the wavelength of 291 nm was adopted.Precision of the method was tested and the value of RSD (n=5) found were 8.08%.