Abstract: Firstly, cable voltage charging by rotating and rubbing on floor was measured referred to standard of IEC 61340-4-5, and category 6 ethernet cable voltage was measured. Secondly, based on measurement of the cable voltage waveform, the cable voltage equivalent RC circuit model was deduced, and exponential function can be obtained to describe the cable voltage, the time constant τ is determined by the cable resistance R and capacity C to the ground. Thirdly, the current, transient electric field and magnetic field was measured while the charged cable discharging on the metal target. At last, the current waveform was compared with MIL-STD-461F CS115 conducted susceptibility, bulk cable injection and impulse excitation. The results show that the CDE current waveform is similar, but current is higher. Therefore, the CDE protection method is required and the EMC testing standard needed to be improved to cover CDE measurement.