In order to better understand the grain size, texture evolution and forming limit major strain of ferritic stainless steel, two kinds of ultrapure ferritic stainless steels (Nb single stabilization and Nb+Ti dual stabilization) with 15wt%Cr content of the same thickness processed by the same annealing treatment have been studied in this work. Ti addition does not improve the r-value as much, but it appears to refine the grain size of the ferrite and increase the {111}〈112〉 texture component in the γ-fiber, especially reduce the planer anisotropy value. The enhancement of the formabilities especially the drawability in forming limit diagram of Nb+Ti dual stabilization 15%Cr ferritic stainless steel mainly due to the refinement of the grain size, higher average r-value and lower planer anisotropy value.