Objective:To investigated the blocking effect of high frequency alternating current signal to nerve action potential conduction. Methods:Frog sciatic nerve was dissected out in the experiments. The amplitude of action potential(AP) and the state of muscle during high-frequency sinusoidal stimulation were observed to determine the blocking effect. Results:The results showed that in a certain frequency complete block could be achieved at the threshold. When the stimulation amplitude increased upon threshold, there was no obvious difference in the character of the block. With an increase in frequency, block threshold also increased. The muscle tetanus due to the block frequency stimulation vanished after a short period signals whose frequency was higher than the block frequency were induced. In the following course, the muscle contraction was blocked by high frequency AC signal. Conclusion:Blocking effect of high frequency AC signal to nerve action potential conduction can potentially provide new methods for clinical applications of electrical nerve block in local anesthesia, acesodyne and spasmolysis.