The objective of this investigation was to study the effect of pH on antioxidative activity of Maillard reaction products (MRPs) from the L-ascorbic acid(ASA)–L-proline(Pro)/L-alanine(Ala) model systems. MRPs were prepared by heating the solution containing ASA and Pro/Ala adjusted to different pHs (4.0, 5.0, 6.0, 7.0 and 8.0) at 140℃ for 2 h. The antioxidative activity of MRPs was evaluated by reducing power, 1,1-diphenyl-2-picryl-hydrazyl(DPPH) radical-scavenging activity and Fe2 chelating activity. The results indicated that reducing power and DPPH radical-scavenging activity reached a maximum with initial pH5. An increase in Fe2 chelating activity of MRPs derived from ASA-Lys/Met model systems was observed as the initial pH increased. Moreover, reducing power of MRPs correlated well the UV-absorbance at 294nm.