Abstract: Objective To investigate the clinical manifestation, electrophysiologic features of patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Methods Fifty-six patients diagnosed as CIDP were enrolled in this study, and their clinical and electrophysiologic features were analyzed. All patients had undertaken the electrophysiological studies and their nerve conductive velocity, amplitude, latency and electromyography were tested and analyzed. The value of those patients was compared with that of the 32 normal persons. Results Protein - cell separation phenomenon were performed in 47 cases (83.9%), and the EMG of patients were showed neurogenic damage. Motor conduction in addition to the proximal incubation period between the two groups had no significant difference, while other comparisons between the two groups had statistical significance. Conclusion CIDP shows widespread damages, and there exists electrophysiological changes given priority to demyelinating with axonal degeneration.