Based on a magnetized radio-frequency (rf) sheath model, we self-consistently simulated the rotational behaviors of two-dimensional (2D) dust Coulomb crystals with particle number N varying from 2 to 100. Motions of particles are tracked by solving their Newton's equations in which various forces acting on the particles are considered. It is observed that these particles can arrange themselves into ordered structures roughly in a plane, i.e., the 2D Coulomb crystals, while rotations of the crystal driven by the azimuthal ion flow are established. The structures of the crystal are found to be similar to those observed in previous experiments. The angular frequency of the crystal rotation is found to be in the order of 10(-2) Hz, and proportional to the strength of magnetic field and inversely proportional to the discharge pressures. Additionally, the intershell or sheared rotations are observed in high magnetic field, while the rigid rotations are commonly observed in small magnetic field. (c) 2005 Elsevier B.V. All rights reserved.