Fluorescence Excitation-Emission Matrix (EEM) combined with fluorescence regional integration (FRI) and parallel factor analysis (PARAFAC) was employed to tracing the properties and behavior of the water-execrable organic matter (WEOM) from landfilled municipal solid waste (MSW) for assessing the biological stability. The 3-components PARAFAC model developed showed the WEOM dominated by two humic-like materials (components C1 and C2) which were highly correlated and behave similarly in this work, and a protein-like material (component C3). The percent fluorescence response P-i,P-n from FRI and maximum fluorescence intensity F-max of the components from PARAFAC proved to be sensitive indicators of the bulk properties and transformation of WEOM during landfill stabilization. C1/C3 F-max ratio was found to be the most sensitive indicator of the biostablization state of the landfilled MSW and can be considered a reliable parameter. These results reveal that EEM-PARAFAC/FRI enabled a rapid and accurate assessment of biological stability of landfilled MSW. (C) 2012 Elsevier Ltd. All rights reserved.