From a biophysical systems perspective, this research suggest edusing emergy synthes is to highlight the fact that the three con-stituents of vulnerability are inseparable entities. This also allowsfor the use of emergy as a common unit to integrate the ener-getic flows between natural and human society for vulnerabilityassessment. The properties of exposure, sensitivity, and adaptivecapacity are interrelated and overlapping, meaning that in eachassessment of vulnerability no single property must be empha-sized over the others. The major challenges of incorporating emergyevaluation for vulnerability assessment include: linking biophys-ical and social realms and their mutual interactions; taking intoaccount the interactive characteristics among the three compo-nents of vulnerability; and evaluating these three components withcomparable emergy units. On the basis of emergy concepts, the pur-pose of this paper is to develop a systemic evaluation frameworkthat will help us to interpret the three components of urban vulner-ability to flooding from emergy concepts; develop emergy indicesto assess urban vulnerability to flooding; and exhibit the spatialheterogeneity of urban vulnerability to flooding via GIS. The pro-posed framework is applied to study Taiwan’s western coastal plainarea. The remainder of this paper will first describe our study designand methodology of how emergy concept is used to interpret thethree components of vulnerability and the development of emergyindices for assessing urban flooding vulnerability. The frameworkof emergy evaluation and indices is applied to the study area toreveal the spatiality of exposure, sensitivity and adaptive capac-ity. The advantages and limitations of using emergy evaluation toassess vulnerability are also discussed.