Caffeyl valine ethyl ester, caffeoyl leucine ethyl ester, caffeoyl methionine ethyl ester, and caffeoyl tyrosine ethyl ester were synthesized by using L-amino acid ethyl ester hydrochloride and caffeic acid as raw materials in the presence of a catalytic amount of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide-hydrochloride (EDC) and 1-hydroxybenzotriene (HOBt) . The structure of the product was identified by mass spectroscopy (MS), nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopies. Then, antioxidant activity and irritation were carefully measured by the DPPH free radicals scavenging, hydroxyl radical scavenging experiments and erythrocyte hemolysis experiments. Four of N-caffeoyl amino acid ethyl esters were synthesized with yields between 75% and 82%. The results showed that after the combination of caffeic acid and amino acid, all the four products showed good inhibition of DPPH free radical and hydroxyl radical activity; caffeoyl valine ethyl ester had the strongest ability to scavenge DPPH free radicals, and its IC50 value was (11.23 ± 0.24) μmol/L; caffeoylmethionine ethyl ester has the strongest ability to scavenge hydroxyl radicals, and its IC50 value is (0.24 ± 0.002) mmol/L. The three caffeoyl amino acid ethyl esters are less irritating to the erythrocyte membrane relative to the caffeic acid monomer. N-caffeoyl amino acid ethyl esters derivatives are more effective than Vitamin C and might serve as new potent antioxidant.