Abstract: A RP-HPLC method was established for the determination of Carboxypeptidase Inhibitor from Potatoes (CPI) .The operation was carried out by applying the sample treated with 80% ethanol a C8 column with the mobile phase of water (with 0. 1%TCA)-acetonitrile (with 0.1%TCA)gradient, monitored at 280nm. CPI was eluted at 35%～40% acetonitrile (V/V), and had a good linearity at the range of 10mg/L to 1000mg/L with R2=0.9982 .The recovery CPI of this method 101.3% . This method has been successfully applied to analysis CPI from various materials and process control during CPI purification.

Key words: reverse phase high performance liquid chromatography (RP-HPLC), carboxypeptidase inhibitor from potato (CPI), potato