The surface modification of nano-hydroxyapatite with polyamidoamine (PAMAM) dendrimer has potential for biomedical applications due to their unique and well-defined secondary structures. This paper presents a facile method to synthesize siloxane-cored PAMAM dendrons modified Hydroxyapatite nanoparticles. Firstly, the siloxane-cored PAMAM dendrons with different generations (G1 to G5, respectively) were synthesized using repetitive reactions between Michael addition and amidation starting from 3-aminopropyltriethoxysilane. Then, hydroxyapatite nanoparticles were synthesized by hydrothermal crystallization method and functionalized with siloxane-cored PAMAM dendrons. These synthesized materials were characterized by using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Thermogravimetric analysis (TGA). The results showed that the PAMAM dendrimer functionalization was carried out successfully and these materials may be applicable in biocomposite material and/or bone tissue engineering. (C) 2017 Elsevier Inc. All rights reserved.