Magnesium fluoridated hydroxyapatite (MgFHA), a modified hydroxyapatite (Ca 10 (PO4) 6 (OH) 2 , HA), can be used as reinforcement in polymeric matrix to improve its properties. It is bioactive, biocompatible and asteoconductive. Despite of these desirable properties, due to the incompatible surface of ceramic nanoparticles with polymers, they tend to agglomerate in polymer matrix which results in undesirable effects on the bio-properties of polymer composites. The aim of this study was to surface modified magnesium fluoridated hydroxyapatite nanoparticles. In this regards, first MgFHA was prepared, then it was surface modified by six different amino acids. Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA) were utilized to characterize the morphology and properties of the obtained modified bioceramic. The modified nanobioceramic were appropriately dispersed in polar and nonpolar solutions. The uniform distribution of MgFHA is a desired condition for polymer/ceramic composite preparation which is highly applicable for biomedical purposes. After modification of nanoparticles, the surfaced modified nanoparticels were used to formed polycaprolactone/ MgFHA nanocomposite. Stainless steel (316L) substrates were coted by surface modified nanocomposite. Resultes showed that surface modified nanocomposite were more bioactive in camparision with unmodified ones, after soaking in simulated body fluid. To observed the corrosion behavior, cyclic polarization test was informed.The reduced corrosion current observed for all of the coated samples, confirmed the significant improvement corrosion resistance of the substrates with nanocomposite coatings. Results suggested that polycaprolactone/ surface modified magnesium fluoridated hydroxyapatite nanocomposite coatings might be potentially useful for biomedical applications, especially as a coated implant for hard tissue treatment. Keywords: Magnesium fluoridated hydroxyapatite , Polycaprolactone, Nanocomposite, Amino acids, Surface modification