To compare the antidromic and orthodromic conduction of saphenous nerve, SNAP's(sensory nerve action potentials) were recorded at both legs of 31 normal adults.

Three methods were used: 1) stimulation at the medial side of the knee and recording at the medial side of mid-tibia, 2) stimulation at the medial mallelous and recording at the medial side of mid-tibia, 3) stimulation at the medial side of mid-tibia and recording at the medial mallelous.

Latency and duration of SNAP's were practically same in all the methods, which meant that there was no difference in conduction velocity between antidromic and orthodromic methods.

The mean value of the amplitude in method 1, 2, and 3 were 8.06, 4.29, 5.33㎶, respectively. Among 62 tests, we could not get SNAP in 2 tests of the third method. The first method of saphenous nerve conduction seems to be the most practical.