During femoral head endoprosthesis replacement for intracapsular fracture of femoral neck in 12 aged patients, bone specimens from different parts of the excised femoral heads were collected, processed and studied under scanning electron microscope. The following findings were observed. (1) Callus tissues formed around trabecular microfractures could be discerned all over the femoral head, however, more numerous in the trabceulae abutting the subchondral bone plate. (2) There was a transformation of the microfracture callus from the early spindle—shape, through remodelling, to the late round or beer—barrel shape. (3) The remodelling of the microfracture callus assumed a special pattern toward the unique structural characteristics of trabecula, i. e. the central zone, transitional zone and superficial zone. (4) The microfracture callus derived from two sources, the cambium layer of the periosteum covering the trabeculae and the marrow stromal cells of the femoral head. Microfracture healing was conducted by these two types of callus tissues.