A better way to cure muscle convulsive disease is inject A type cretoxin into the lesion muscles . The lesion muscles can be selected more exactly through the electromyogram-lead instrument. More and more information indicate that it will improve curative effect and make less bad effect for the disease which can be cured by botulinium toxin. And now how to find the lesion muscle is through the doctor's feeling and experience or recur to electromyography which brings much difficult. The text developed an electromyogram-lead instrument, which is simply operate, lower cost and easy to find the lesion muscle.The electromyogram-lead instrument include needle electrode and electromyogram-lead instrument which matchs it. The signal import from the needle electrode then it will be magnified in two levels through the amplifier which is low-yawp. The signals output from the front level amplifier couple into the back level amplifier through the transformer. The front level circuit is made up by high input impedance and low-yawp amplifier and isolated power supply. The circuit collects and dispose primaly electromyogram signal. The function of the back level circuit is to amplify the signal from the front level circuit father. And it will put the end signal into the computer through insulated steps. The signal will be filtered by the program and transferred into sound and image.The electromyogram-lead instrument use absolute isolated power supply and the signal transform is also isolated. The instrument measures up to the electric safe rules of the medical instrument. Remove the industry frequency is be emphasized.