The transfer impedance determined on Frank's lead system and McFee, Parungao's lead system using canine torso model was studied and following results were obtained. A simplyfied canine torso model was made, which was a cylinderic type imitated faithfully the transverse section in the fifth intercostal space of the canine. The canine which was used as a model has a body weight of 16.2kg. Its torso dimensions were left to right of 14.0cm, front to back of 19.0cm and height of 55.0cm. Its form was an oval on the whole shape with more gently curved surface on the front. Heart center on the dog determined by the X-ray located on the position which was 0.75cm to the left, 2.9cm to the front from the body center in the fifth intercostal soace. The definite dipole was placed on the heart center of the torso filled with 0.1% NaCl solution. Electrode position on the torso surface is defined by two quantities; levels (number 1 throngh 10) and angles in the transverse plane. The levels were separated each other at a distance of 3cm. Thus determined level 6 correspond to heart center level of the canine. The angles were taken each 5 or 10 around the cylinder whose plane passed precisely through the center of the body. Thus, potentials were determined and image surface was drawned on the loops. Image loops were oval and located on left anteriorly and slightly inferiorly from the heart center. As a result, canine image loop was found to be clearly different from the shape of the human's one which has a shape of a pear projecting slightly to the back. Then, normality and orthogonality were examined on the torso with the Frank's orthogonal lead system for human and with the McFee, Parungao's axial lead system for dog resulting the latter to be better than the former
