Rhythmic is a basic element of human life.During the fast repetitive movements cortical potential represents different characters from those of separate movements performed slowly.In this article,we record the electrocorticographic(ECG) activity from the brain surface of two epileptic patients during fast repetitive movement in two kinds of rates,analysis movement-related power and movement-related coherence of ECG signals and uncover that the power on special frequency band goes up while the coherence goes down.The two indexes appear statistically significant difference between fast and slow rate movement.Analysis of the coherence between different functional regions shows that SMA may be related to the movement rate.