Abstract: Cytokinesis, themechanical separation of a mother cell into two daughter cells,occurs through a series of stereotypical shape changes.Cytokinesis is accompanied by mechanical phenomena through almostevery level. The formation of cortical subdomains with differentstiffness and viscoelasticity is critical for the resulting cellshape change. The recruitment of specific actin cross-linkingproteins is important for the local change of the stiffness. It isessential to understand fully the process of cells changing theirshapes, the cellular material properties achieving successfulcytokinesis, and the basis of molecular biology of cytokinesis. Inthis review, the mechanical properties of cells, the mechanics ofcytokinesis, and the molecular biology basis of cytokinesis arediscussed.