A position-marking apparatus for image scanning comprises a carrier and a colloidal solvent. The colloidal solvent is disposed at the carrier, and the colloidal solvent includes a solvent and a plurality of developing particles. The colloidal solvent can be marked onto the skin of a patient via the position-marking apparatus such that an image-developing machine may precisely develop the patients affected area. Therefore, the fault cure caused by positioning error can be effectively reduced.一種用於影像掃描之定位標示裝置,其係包含一載體及一膠狀溶液,該膠狀溶液係設置於該載體,該膠狀溶液係包含一溶液及複數個混合於該溶液之顯影微粒,本發明係藉由該定位標示裝置將該膠狀溶液標記於患者之皮膚,以利由一影像顯影裝置精確地顯影出標記於患者之皮膚所對應之患部,故此能減少因定位失誤所造成之醫療疏失。100...用於影像掃描之定位標示裝置110...載體111...上表面112...下表面120...膠狀溶液121...溶液122...顯影微粒130...背膠140...離型膜