The usage of electromyography is customized in the diagnosis of the neuromuscular disorder and the determination of motor conduction velocity is important in the diagnosis of the peripheral nerve lesion and in the posing of the site and severity of nerve damage. Although the radial nerve is frequently involved in generalized neuropathy and in entrapment syndrome, relatively fewer reports have appeared in the literature regarding the radial nerve. The purpose of this study is to determine the normal data of the motor conduction velocity of the proximal and distal segments of the radial nerve. The radial nerve fibers supplying the extensor indicis muscls muscle was stimulated at Erb's point, above the elbow and in the distal forearm and its muscle action potential was sampled. Seventy-four radial nerve were studied in thirty-seven healthy young subjects. The results obtained were as follows; 1. The mean proximal velocity was 70.7±6.8m/sec and the mean distal velocity was 57.6±4.3m/sec. 2. In any case tested, the proximal velcity was over 55m/sec. 3. The proximal velocity was faster than the distal velocity and the mean difference was 13.1m/sec In only 7 of the 74 nerves tested, the proximal velocity was slower than the distal velocity and the difference of Sm/sec was the most reversal. 4. The velocity in dominant limb was faster than that in nondominant limb. 5. There were no significant difference between the sexes.