PURPOSE: To provide a high-strength core member having high buckling strength.

CONSTITUTION: A high-strength core member is formed of a high-strength material and comprises at least one core C which receives a compressive load. The core C is enclosed with a housing H. In the space between the inner wall of the housing H and the core C, an internal packing material, such as a grout G which constrains the core C sideways is provided. The housing H is shorter than the core at all load stages, including the ultimate load of the core member. Thus, compressive load is applied only to the core member, and no jointing takes place between the core member and the internal packing material at all load stages including the ultimate load.