Abstract: A portable electrocardiograph comprising a housing and a second electrode which is provided on one end of the housing, characterized in that a clamping cover which tends to close automatically is provided on the other end of the housing; an oval finger hole is provided between the clamping cover and the housing; the lower half of the inner wall of the finger hole is defined on the housing; the lower half of the inner wall is provided with a first electrode; and the upper half of the inner wall of the finger hole is provided on the clamping cover, such that the present invention provides the portable electrocardiograph of simple structure, convenient use, and high reliability for heart disease sufferers.