A thin film of a medical implant includes a surface, a plurality of walls and a plurality of paths. The walls are disposed on the surface, and formed to shapes of arc. The paths are disposed on the surface, wherein each of the paths is located among the walls. The walls and paths have a plurality of holes. According to the thin film of the present disclosure, the walls are formed to shapes of arc, and have no acute anger, whereby the biological cells can helpfully grow and attach on the thin film quickly. Furthermore, the thin film has the holes, which provide cell tissue, such as pseudopod, tentacle, etc. of the biological cells to grow and attach therein, whereby the biological cyto-affinity of the thin film can be increased so as to increase the biological cyto-compatibility of the medical implant.