The invention relates to a system and method for measuring electrical characteristics of biological cells through a nano-electrode array under physiological conditions. The system consists of the nano-electrode array, an inverted or upright optical microscope, a probe control module and an electrical signal processing module. The system is arranged in a culture environment suitable for cell in-vitro growth, the electrical characteristics of a single cell are detected through the nano-electrode array and probes, the strength of an electrical signal is measured and recorded according to selected points or areas, and the electrical characteristics of a cell body are obtained on a nano-scale. The invention aims to improve an existing micro-electrode-array-based method for measuring the electrification amount of the biological cells by using the nano-electrode array so as to provide the method and system capable of measuring the electrification amount of the biological cells, applying an electric excitation signal to the single cell for observing the change of the single cell and also detecting the electrical characteristics of the cell by utilizing the probes.