Abstract: Proposed is a nitinol nanofiber with an average surface roughness that is enhanced through mechanical and chemical treatments. The enhanced surface roughness improves biocompatibility and promotes tissue growing, thereby improving the bioavailability of the nitinol nanofiber. The nitinol nanofiber undergoes infrared irradiation whereby the nitinol fiber exhibits improved tensile strength, elastic modulus, and maximum restorative stress. Therefore, fatigue fraction does not easily occur in the nitinol fiber even when the nitinol nanofiber has a constant roughness. The present invention provides bio-use or medical nitinol nanofibers that are highly biocompatible.