Objective To investigate the clinical and electrophysiological features of chronic inflammatory demyelinating polyneuropathyrn(CIDP) . Methods The clinical symptoms and signs of 11 patients with CIDP were studied, motor conduction velocity( MCV), sensory con-duction velocity (SCV) and Electromyography (EMG) were also respectively carried out on 54 motor nerves, 28 sensory nerves and 21 musclesof these 11 cases. The amplitudes of compound muscle action potential(CAMP) obtained from distal and proximal ends were compared to as-certain the presence of conduction block (CB) by stimulating the segments starting from the distal ends. Results More than 3 nerves werefound involved in 10 out of 11 cases, slow MCV were found in 52%, prolongation of the distal latency in 64%, reduction of the amplitudes ofCAMP in 68%, CB in 26%, slow SCV in 85. 7%. EMG revealed neurogenic damage in 81%. Conclusion CIDP is a peripheral de-rnmyelinating neuropathy involving not only the prox imal and distal segments but also the sensory and motor nerves. If there were no conditionsto perform nerve biopsy, testing of protein in CSF and electrophysiology mightbe of important diagnostic value for CIDP.