Several different groups of filler metal are known to be compatible in welding of AA6xxx series. The aim of this investigation is to study the effects of different filler alloys toward mechanical properties and microstructure of welded AA6061 aluminium alloy using gas metal arc welding. Single V butt joint configuration has been used for joining the plate’s. Butt-joint welds were made on 6 mm thick plates using 21 – 22 V arc voltage. Tensile test was carried out using 100kN, electro-mechanical controlled hydraulic Instron 8801 universal testing machine. The results showed that the yield strength of base metal were 330 MPa and while the yield strength of ER5356 joints and ER4043 joints were 200 MPa and 235 MPa, respectively. The difference properties of strength in both weld metal was due to the difference major element in the both filler composition. The amount of silicon content in ER4043(Al-Si5%) filler is believed to play a role in the mechanical strength on weld metal. Microstructural examination was carried out using a light optical and electron microscope. The different filler alloys give different weld metal microstructure.