Facial expression is a common language for all humans. We can observe small variety of facial expression from other people and then realize their feeling and ideas. The coordination of facial muscles performs every kind of facial expression. Therefore, we can measure the fEMG, responding the facial emotion, to observe the phenomena of physiology and psychology. In addition, the fatigue is also kinds of human emotion characteristics. The fatigue degree can be detected by the degradation of the facial muscle activity[20]. In this section we discuss the fEMG applied to the emotion evaluation.