The additive manufacturing (AM) of metallic parts uses different techniques with promising characteristics and results. Nowadays technologies classified as Powder Bed Fusion and Direct Energy Deposition (DED) are the most used. The first one achieves parts with good dimensional accuracy and surface roughness while the second (using powder or wire as filler metal) is suitable for the fabrication of bigger components due to its high deposition rate. Amongst DED technologies, Wire and Arc Additive Manufacturing (WAAM) is promising especially because of its high deposition rate, low cost raw materials, low material loss, and capability to manufacture large parts (with an automatized system). In the industry, the aluminum is used frequently, principally because its low density and mechanical properties. Aluminum alloys are specially employed in transport such as cars, railways and particularly in aeronautic industry. Amongst the various arc welding processes, the Cold Metal Transfer (CMT) process is a promising one for WAAM , thanks to its controlled current waveform and filler wire feeding that allow regular deposited weld bead. The present study focuses on the implementation of CMT welding generator using an aluminum alloy wire (Al5Si). The aim is to identify the relationships between the CMT welding parameters and the physical results, in order to find the most suited parameters allowing a regular deposit. The CMT work parameters are first evaluated in a qualitative way in order to observe its effects on the morphological aspect of the deposited weld beads. A quantitative analysis of the deposition rates and energies according to the CMT parameters is also carried out. Finally, first attempts of multi layers addition are presented, and relationship between of these last results and CMT parameters is discussed.