The purpose of this study investigated the anesthetic effects of lidocaine gel by phonophoretic transdermal delivery. The anesthetic effects were evaluated by two aspects as quantitative sensory testing and sensory nerve conduction study. Twelve healthy males(aged $23.25{pm}2.09$ years) were studied. Exclusion criteria were ; pain, history of sensory disturbances and skin conditions in the areas to be examined. The subjects were divided into two groups; group I(lidocaine gel without ultrasound) and group II(lidocaine gel with ultrasound). The following results were obtained; 1. In changes of tactile threshold and electrical pain threshold, all groups were significantly increased(p<0.05). 2. In changes of electrical pain threshold, it was significantly differenced between the groups(p<0.05). We conclude that the transdermal delivery of lidocaine gel by phonophoresis has a possibility to use for surface anesthesia and the pain control of the superficial tissue.