Each conspecific biological individual has a unique body composition. This diversity may result in the variability of basic electric characteristic in electrochemical impedance spectroscopy (EIS) measurement process. Morphological characteristic of EIS is presented for the first time in this article to eliminate the measurement variability of carps from different origins. This paper proposed a method to extract quantifiable parameter as freshness indicator from morphological characteristic. The relative standard deviation of morphologic characteristic parameter obtained from 20 carps with different origins in the same storage time was only 4.6% while the corresponding values of impedance module and phase angle were between 7.8% and 20.1%. In addition, prediction coefficient of determinations (R-2) used morphologic characteristic parameter as freshness indicator was 55%-90% up on that used traditional parameters. As a completely new perspective about EIS detection, morphological characteristic method could be applied in other objects of EIS analysis and promote commercialization of EIS detection. (C) 2016 Elsevier Ltd. All rights reserved.