PROBLEM TO BE SOLVED: To provide a bone fixation screw for a living body capable of avoiding stress shielding and metal allergy, being less prone to fracture, having mutually contradictory implanting property and initial fixability, and exerting high bone binding property.SOLUTION: A bone fixation screw 1 for a living body comprises: a substantial part 5 that has a screw base 21 formed with a thread base part 23 rotating at least one revolution, at a peripheral side face and a surface porous layer 6 integrally formed of same biocompatible polymer as that of the substantial part 5, on a root 25 of the screw base part 21. At least a part of the surface porous layer 6 formed on the root 25 has the thickness of 50-500 &mum, and a height difference of the surface porous layer from the thread base part 23 lying adjacent to the root 25 is 200-800 &mum.
