Abstract: Objective:To establish an HPLC method with pre-column derivation for determining the contents of amino acids in Morindae ficinalis How of different processed samples.Methods:The amino acids were ultrasonically extracted with water and determined by RP-HPLC using phenyl isothiocyanate (PITC) as the pre-column derivation reagent.HPLC method was employed and Sinergi 4u fusion-RP (Phenomenex, 250mm×4.6mm, 4μm) was used at column temperature of 35℃.Results:There were 14 kinds of free amino acids in Morindae ficinalis How, which had been growing for 4～5 years.The total amino acids of wine steamed increased approximately 14.8% than raw products, salt steam and licorice root system was essentially the same, salt fried amino acids decrease of approximately 12.4%, wine fried decrease of approximately 43.9%.Conclusions:This method was simple, sensitive, accurate and reliable in results.The content of free amino acids constituents were influenced by processed by different ways.