Abstract:This research proposal provides corrosion behaviour of Manganese added Magnesium and its alloys. Magnesium is lightest of all Engineering metals and therefore it is attractive alternatives for Steels and aluminium. The corrosion of Mg and its alloys continues to be a major technological issue preventing wider usage of such alloys. Different corrosion like Galvanic corrosion, pitting corrosion, intergranular corrosion (IGC), filiform corrosion, crevice corrosion, stress corrosion cracking (SCC), and corrosion fatigue (CF) were already discussed for Mg alloys by different researchers [13] . In Magnesium-Aluminium (Mg-Al) alloys, the formation of intermetallic Al 8 (Mn,Fe) 5 phase improves the corrosion resistance by removing elemental iron particles from the Mg and its alloy [10] . The corrosion rate examined via electrochemical and Weight loss method (Immersion test). It was seen that samples with Mn additions exhibited an increased Fe impurity tolerance level. This indicates that the Mn addition was able to moderate the effect of the Fe impurity on the corrosion of the Mg alloy. In addition, influencing factor of corrosion behaviour of Mg alloys like effect of allying element, Microstructure and secondary phases, grain size, effect of welding and heat treatment were discussed.