One of the most important needs of the industries is the improvement of processes in the bonding of various aluminum alloys. In order to achieve a suitable weld profile with the desired mechanical properties and structure, the biggest challenge is the aluminum alloy joints. The purpose of this study was to investigate the effect of adding TiO 2 nanoparticles on the microstructure, mechanical properties and corrosion properties of the welding metal in a similar bonding of AA5083 aluminum alloy using GTAW process using ER5356 metal filler. In this direction sheets of thickness 2mm were prepared from AA5083 alloy and the connection was made during one pass. To investigate the effect of nanoparticles on weld metal, TiO 2 nanoparticles were added to the weld pool by two methods of coating on ER5356 metal filler and coating on AA5083 base metal. In order to evaluate the microstructure of the optical microscope, scanning electron microscopy and elemental analysis were used. To evaluate mechanical properties, the Vickers micro hardness test, cross-sectional tensile test and shear stress test were used. Also, to investigate the corrosion properties of the welding section, a TOEFL polarization test was used in 3.5% sodium chloride. The microstructural evaluation revealed that the size of the grains in the weld region of the welded samples of nanoparticles was reduced by both methods. Also, microstructural studies showed that microstructure in welding using filler metal containing nanoparticles is more homogeneous than welding with base metal containing nanoparticles. Mechanical properties tests indicate the improvement of mechanical properties such as the hardness and shear strength of the bonded samples with the presence of nanoparticles in the weld metal. It was also observed that the use of TiO 2 nanoparticles improves the corrosion properties of the weld metal. According to the results of this study, bonding of GTAW using nanoparticle filler metal due to the uniform distribution of nanoparticles in the weld pool results in a uniform and homogeneous structure that has the best microstructural, mechanical and corrosion properties. keywords : Aluminum AA5083, TiO 2 nanoparticles, arc welding of tungsten gas, mechanical and corrosion properties.