Zymomonas mobilis ZM4 is famous Gram-negative bacterium that can efficiently produce ethanol from glucose, fructose, and sucrose by utilizing the Entner-Doudoroff pathway. The genome-scale metabolic model of Z. mobilis is reconstructed based on its annotated genes, literature, physiological and biochemical information to analyze the metabolic characteristics of this bacterium.The features of Z. mobilis were examined using constraints-based flux analysis. First, the physiological changes of Z. mobilis as it shifts from anaerobic to aerobic environments were investigated. Then the intensities of flux-sum, which is the cluster of either all ingoing or outgoing fluxes through a metabolite, and the maximum in silico yields of ethanol for Z. mobilis and Escherichia coli were compared and analyzed.