The objective of current study is to determine antioxidant activities of Maillard reaction products (MRPs)obtained from Maillard reaction model systems with different combinations of 15 individual amino acids and3 different sugars(glucose, fructose and lactose). Antioxidant activities of MRPs were determined usingtechniques of measuring DPPH and ABTS-radical scavenging activities. The results indicated that radicalscavenging activities of MRPs were significantly increased compared to individually thermal treated amino acidsand sugars. Among the model systems, the systems containing glycine or lysine + sugars (glucose, fructose andfructose) displayed the stronger DPPH and ABTS radical scavenging activities than other model systems. Inaddition, when the thermal treatment time was increased, radical scavenging activities of MRPs were increasedin a reaction time-dependent manner. Further investigation using bioassay-directed fractionation was performedusing two model systems (glycine+glucose, lysine+glucose) which displayed the strongest radical scavengingactivities. The reaction solution were subjected to partition with a different polarity of solvent (hexane, ethylacetate, n-butanol, and water) for evaluation of their radical scavenging activity. Among them, ethyl acetatefraction exhibited the strongest DPPH-radical scavenging activity in both model systems.