A portable electrocardiograph, in which an exposed electrode is arranged on the end face of one end of a housing, characterized in that: the other end of the housing is of a comfortable structure for holding the comfortable structure for holding is provided with the other exposed electrode and the geometric center of the comfortable structure for holding is of an offset toward the other end of the housing and one of the two transverse sides, and a measuring key is arranged in the geometric center of the comfortable structure for holding. The present invention is of a humanized and unique holding structure shape, which ensures the wrist, the arm, and the trunk of the user are closed to form a relative space, thus allowing the user to measure in natural and correct posture so as to make sure the monitored data to be accurate and reliable.