A simple isocratic HPLC technique has been developed for the quantitative analysis ofphenolic acids(PAs) in fruits and vegetables.Nine benzoic and cinnamic acid derivatives wereseparated in less than 30 min,and the resolution was all more than 1.23.The ranges of linearityfor PAs standards were 0.2-100 ng,even up to 600 ng(r=0.983-1.000) and the detection limitswere 0.02-0.24 mg/kg.Samples of fresh vegetables and fruits were extracted with 80%,methanol and ethyl acetate,then purified with C_(18) Sep-Pak cartridge and determined byHPLC.This method was applied to the determination of PAs in 7 kinds of fruits andvegetables,i.e.,apple,pear,Chinese cabbage,cauliflower,turnip,soybean sprout and whitegrape wine.The content of the 9 PAs varied widely in the 7 kinds of foods studied.The averageconcentrations of chlorogenic acid in apple(100.2 mg/kg) and pear(30.8 mg/kg) were quitehigh,and sinapinic acid was remarkable(42.5 mg/kg) in Chinese cabbage,and protocatechuicacid had the highest concentration of all the P A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were prepared in less than 30 min, and the resolution was all more than 1.23.The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limitswere 0.02-0.24 mg / kg.Samples of fresh vegetables and fruits were extracted with 80%, methanol and ethyl acetate, then purified with C_ (18) Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits andvegetables, ie, apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and whitegrape wine. The content of the 9 PAs varied widely in the 7 kinds of foods studied. The averageconcentrations of chlorogenic acid in apple (100.2 mg / kg) and pear (30.8 mg / kg) were quitehigh, and sinapinic acid was remarkable (42.5 mg / kg) in Chinese cabbage , and protocatechuicacid had the highest concentr ation of all the P