Gallium nitride (GaN) and related compounds have attracted considerable academic and commercial interest because of their potential applications in blue, green and UV optoelectronic devices and high-temperature electronic devices[1]. For most of the GaN-based materials used for devices fabrication, the ions implantation is one of the key methods of doping in GaN-based semiconductor technology. The study of defects from the device fabrication and device performance is very important though GaN is immune to various environments. These defects are responsible for the modification of the physical properties of the material. The defects can be widely introduced by artificial irradiation, such as electron, proton, neutron and various ions irradiation on GaN epi-layers, grown by MOCVD technique. Shift heavy inert gas ions (SHI) can create point defects along its trajectory, resulting in tracks in a solid[2]. In this work, we present the microstructure damage of GaN epilayers irradiated with 5.3 MeV Kr23+ and 2.3 MeV Ne8+ ions to different ion fluences using Raman scattering spectroscopy. Gallium nitride (GaN) and related compounds have approvals academic and commercial interest because of their potential applications in blue, green and UV optoelectronic devices and high-temperature electronic devices [1]. Most of the GaN-based materials used for device fabrication , the ions implantation is one of the key methods of doping in GaN-based semiconductor technology. The study of defects from the device fabrication and device performance is very important though GaN is immune to various environments. These defects are responsible for the modification of the physical properties of the material. The defects can be widely introduced by artificial irradiation, such as electron, proton, neutron and various ions irradiation on GaN epi-layers, grown by MOCVD technique. Shift heavy inert gas ions (SHI) can create point defects along its trajectory, resulting in tracks in a solid [2]. In this work, we present the microstructure damage of GaN epilayers irradiated with 5 .3 MeV Kr23 + and 2.3 MeV Ne8 + ions to different ion fluences using Raman scattering spectroscopy.