A series of amide derivatives of 3,4,5-trihydroxyphenylacetic acid was synthesized in two steps. The antioxidant activities were evaluated by using four different in vitro models such as ABTS and DPPH radical scavenging activity and FTC and TBA anti-lipid peroxidation activity. Most of compounds were more powerful radical scavengers than vitamin C and were comparable to Trolox. It was found that there were no direct correlations between radical scavenging and anti-peroxidation activities. The inhibitory activity of compound on lipid peroxidation showed remarkable dependency on both the number of phenolic hydroxyl group and the length of methylene linker in N-arylalkyl group of amide. Compound 14, a conjugate of 3,4,5-trihydroxyphenylacetic acid and dopamine, was found as powerful antioxidant as propyl gallate in all four antioxidant assays.