Abstract: The stabilizing mechanism of toroidal rotation on the tearing mode is studied using the 3D toroidal resistive magnetohydrodynamic code M3D. It is found that the dominating mechanism, either the centrifugal effect or the Coriolis effect, depends on the specific pressure β and rotation frequency Ω. On the premise that Ω is sufficiently large, when β is greater than a critical value, the effect of the centrifugal force is dominant, and the stabilizing effect mainly comes from the modification of equilibrium induced by the centrifugal force; when β is less than a critical value, the stabilizing effect from the Coriolis force overcomes that from the centrifugal force. However, if Ω is small, then the effect of equilibrium modification due to the centrifugal force is not significant even if β is large. Finally, the results showed that toroidal rotation shear enhances the stabilizing effect.