An amino acid amphiphile, N-(4-decyloxy-2-hydroxybenzylidene)glycine, was synthesized. Surface tension measurement, dynamic light scattering, and transmission electron microscopy were used to investigate its surface activity and aggregation in solution. All behavior was sensitive to the pH value of the solution. It was found that these properties occur at pH = 12, which is different from the usual situation for carboxylate amphiphiles. The abnormal behavior can be attributed to the formation of a dimeric structure at pH = 12.0. Vesicles were found in this kind of system, which are stable even at the concentration of transition metal ions up to 1 mM. This phenomenon was attributed to the formation of complexes.