A wearable medical sensor system includes a piece of clothes (100) and an elastic bounding layer (200) attached in the clothes (100). The piece of clothes (100) includes a main body (110) with a shape symmetric on both sides with respect to an axis of symmetry (101) and a couple of sleeves (120) symmetrically connected to both sides of the main body (110). At least a part of the main body (110) is surrounded by the elastic bounding layer (200). First to Fifth electrodes (310/320/330/340/350) are attached on the elastic bounding layer (200) corresponding to the same surface of the clothes (100). The elastic bounding layer (200) is more stretchable and more contractible than the clothes (100).
