Forming Limit Diagram (FLD) of a ferritic stainless steel sheet (type 409L) was numerically investigated using three (plane stress) yield criteria of the Hill's (1948), Barlat's (1989), and Barlat's (2003) along with the comparisons to experimental result. The theory of Maciniak- Kuczynski was used to calculate the limit stains in the FLD. The comparisons between numerical predictions and experimental results show that the Barlat's (2003) function predicts the formability of the present material accurately.