The present invention relates to a self-deformation metal marker for marking an object to be marked in a body during radiographic inspection or treatment, which is made of a memory alloy with a transformation temperature of 20 - 37°C. Under the condition of temperature lower than the transformation temperature, the marker is shaped to be a straight line segment the length of which is from 3 mm to 100 mm and the cross section with the diameter of 0.1-1.6 mm is a circle or a polygon, and under the condition of temperature higher than the transformation temperature, the shape of the marker is changed into a straight line segment having a marking ball with the diameter of 1 mm-5 mm in the middle thereof and/or having one or two folded or helical ends. The metal marker can be implanted in a position in the body to be marked using a fine puncture needle, so that the puncture damage caused by a larger puncture needle is avoided. The shape which has a relatively large marking ball and of which both ends are curved in a folded or helical manner is presented in the body, so that x-ray fluoroscopy or development under CT is easily performed, and moving and shifting will not occur in the body, thereby the marker can accurately locate a target, and particularly is suitable for being placed in a target area of a tumor to be treated by radiotherapy.Linvention concerne un marqueur métallique auto-déformant permettant de marquer un objet à marquer dans lorganisme pendant un examen ou un traitement radiographique, ledit marqueur étant constitué dun alliage à mémoire de forme dune température de transformation de 20 à 37 °C. Lorsque la température est inférieure à la température de transformation, le marqueur prend la forme dun segment rectiligne de 3 à 100 mm de long et dun diamètre circulaire ou polygonal de de 0,1 à 1,6 mm lorsque la température dépasse la température de transformation, le marqueur change de forme et le segment comporte au milieu une bille de marquage dun diamètre
