A dynamic bone anchor is provided comprising an anchor member (1, 1', 1") having a first end (11) and a second (12) and a tubular section (13) between the first end and the second end, a longitudinal axis (L) extending from the first end to the second end, an outer surface and a bone engagement structure (14) for engaging the bone in at least a portion of the outer surface； and a longitudinal core member (2, 2', 2", 2'") being at least partially provided in the tubular section (13) and being connected to the anchor member at a second portion (22a) of the core member and having a first portion (21a) that is not connected to the anchor member and that is movable with respect to the anchor member, characterized in that the core member is made at least partially of a first material that comprises a Ni-Ti based shape memory alloy, preferably the first material is Nitinol.本案提供一種動態骨骼，包括固定器構件(1,1',1")，具有第一端(11)和第二端(12)，以及介於第一端和第二端間之管狀段(13)，從第一端延伸至第二端之縱軸線(L)，外表面和把骨骼結合於外表面至少一部份之骨骼結合結構(14)；縱向芯部構件(2,2',2",2'")，至少部份設在管狀段(13)內，在芯部構件第二部份(22a)連接於固定器構件，並有第一部份(21a)，不連接於固定器構件，可相對於固定器構件運動，其特徵為，芯部構件係至少部份由第一材料製成，包括Ni-Ti質形狀記憶性合金，第一材料最好是鎳鈦諾。
