The water quality has always been a concern throughout the recent industrial development. The current available methods are based on the culturing process of the Escherichia Coli (E. coli) to generate observable changes including the color change by means of the staining process of gram-negative bacteria. However, these methods suffer from the long detection time and cannot provide rapid decision-making to avoid the outbreak. This proposed research is to tackle the quantification by observing the impedance change of different quantities of E. coli cultured and to study the relationship between the quantity and the impedance change on a glassy carbon electrode.