In our research, we aim to reconstruct the closed loop of the brain and body for stroke rehabilitation. Stroke patients need to be supported externally when trying to move paralyzed parts of their bodies. In order to know the onset time of voluntarily motions of the patients, the motion intention needs to be detected. If people try to move voluntarily, Movement related EEG is generated. However, the signal includes a lot of noises. In this paper, we propose a method to detect motion intention by EEG. Then, we study on utility of the proposed method by analysis result of a large number of data.