The pH of Maillard reaction products (MRPs) derived from the Gly model system (Gly) decreased markedly as heating time increased. However the Digly model system (Digly) exhibited the highest increase in absorbance at 294 and 420 nm. Moreover, the loss of fructose and degree of sugar enolization in MRPs derived from the Trigly model system (Trigly) was the highest, whereas the glycine oligomer content in the Digly noticeably decreased as heating time increased. Furthermore, the gel permeation chromatograms (GPC) patterns of all MRP samples exhibited rising intensities as a function of the heating time, whereas the major peaks of each MRP sample were eluted at different retention times as glycine oligomer. Antioxidant activity of each MRP sample was investigated by $Fe^{2+}$ and $Cu^{2+}$ chelating activity, Trolox, ABTS, 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity, and ferric reducing ability of plasma (FRAP) assay. MRPs derived from the glycine oligomer were found to be effective antioxidants in different antioxidant activity assays.