Over the past decade, nanoparticles have received a lot of attention due to their special physical and chemical properties. This interest is due to the fact that their properties are different from their bulk material. More specifically, gold nanoparticles can be used in many fields: semiconductors, biosensors, catalysis, and biomedicine (1). It can be synthesized by numerous different methods, for example by radiation (2), vapor deposition (3), electrochemically (4), and thermal decomposition (5). Furthermore, it can be attached to carbon nanotubes to synthesize a functional large metal/CNT hybrid catalytic material. Carbon nanotubes have been one of the most exciting pieces of research since their discovery in 1991 by Iijima. This article will point out a method to support gold nanoparticles on multi-walled carbon nanotubes (MWCNTs) using synchrotron X-ray reduction (6). Synchrotron radiation, similar to cyclotron radiation, is electromagnetic radiation. The acceleration of charged particles to high speeds produces this electromagnetic radiation. His theory was first examined by Schwinger. Synchrotron radiation plays a vital role in emerging technologies and pure science. In this study, synchrotron X-rays were used to attach gold nanoparticles onto MWCNTs. The different shape of the Au/CNT hybrid was observed by transmission electron microscopy (TEM) and identified using energy dispersive spectroscope (EDS). First, the MWCNTs were boiled in nitric acid for 3 to 6 hours to be purified. After purification of the MWCNTs, they were dispersed in 50 mL of distilled water using ultrasound. Subsequently, 0.4 mL of 0.1 M NaOH and 1 mL of 0.05 M HAuCl4·4H2O were added to the MWCNT solution, respectively. The following reaction illustrates that some hydroxides and solvats...... half of the paper .......S. Yeh, YS Yang, YP Lee, HF Lee, YH Yeh, CS Yeh, Formation and characteristics of Cu colloids from CuO powder by laser irradiation in 2-propanol, J. Phys. Chemistry. B 103 (1999) 6851–6857.3- AA Ponce, KJ Klabunde, Chemical and catalytic activity of copper nanoparticles prepared by metal vapor synthesis, J. Mol. Catal. A: Chemistry. 225(2005) 1–6.4- MT Reetz, W. Helbig, Size-selective synthesis of nanostructured transition metal clusters, J. Am. Chemistry. Soc. 116 (1994) 7401–7402.5- YH Kim, DK Lee, BG Jo, JH Jeong, YS Kang, Synthesis of Oleate-Coated Cunanoparticles by Thermal Decomposition, Colloid Surf. A 284–285 (2006) 364–368.6- Kuan-Nan Lin, Tsung-Yeh Yang, Hong-Ming Lin, (2007). A new method for supporting gold nanoparticles. Chinese Society of Particular Studies and Institute of Process Engineering, Chinese Academy of Sciences. 5, pp.237–241