The study was performed in fifteen edentulous subjects with the EMG activity were recorded at the varying occlusal vertical dimension maintaining constant bite force value of 4kg.The results showed that maintaining constant bite force the amplitudes of EMG activity of the anterior temporal and masseter muscles are decreased with increasing the occlusal vertical dimension and correlation relation between them,that there is a stable region about 1.0mm for the anterior temporal muscle and about 1.5mm for the masseter muscle during the changes in electrical activity.It is represent that there is a physiological region of the occlusal vertical dimension for edentulous patient.