This chapter provides an overview of corrosion of metals. It describes the general factors that influences metal corrosion. Over the years, there have been numerous studies on the rates of corrosion of metals in sea water. From various studies, it is now possible to identify the major factors that affect metal corrosion. These factors are metal composition, water composition, temperature, marine growth, seabed composition, and extent of water movement. The combined effect of all these complex and often interrelated factors is that each object must be considered individually when attempting to evaluate its corrosion history or when considering its recovered condition. Till date the available literature on corrosion factor prejudiced by the bacteria, which was predominantly focused on Sulfate Reducing Bacteria (SRB) that usually reside on sulfate (terminal electron acceptor) because SRB are often found at pitting sites.