Forming limit diagram (FLD) is one of the important methods to identify the formability characteristics of sheet metals. The limiting drawing ratio (LDR) is generally used to express the draw ability of sheet metal. Galvanized steel (GI) sheets are widely used in various significant and common applications such as automotive parts, house hold things, construction fields, and electrical appliances. All these applications require superior formability characteristics of galvanized steel sheets with high corrosive resistance, superior quality and durability. Hence understanding the formability of GI steel sheets is highly important to identify the range in which defect free components can be economically manufactured. In this study the formability characteristics of Galvanized steel sheets are investigated with an aid of FLD and LDR. The forming limit diagram of GI steel sheets was constructed using Nakazima tests and tensile tests results. The cup drawing test was carried out in order to find out the Limiting Drawing Ratio and failure criteria of the GI sheets.