The authors investigate the magnetization reversal process of a new structure ferromagnetic submicron dot composed of lateral gradient magnetization by micromagnetic simulation. The reversal process in this structure initiates at both edges along and perpendicular to the applied magnetic field due to introducing demagnetizing field from the interface of gradient magnetization. It leads to the two-stage nucleation process in the structures. Based on numerical analysis, a submicron dot with quarter lateral gradient magnetization is proposed to control the chilarity of a vortex, which is important for the application using the vortex's chilarity