Among mechanisms of cortical ingression regarding cytokinesis, contractile ring hypothesis is the most important one.But it is nohow the conclusive one.Some alternative models have been proposed recently and found to be consistent with experimental observations or to be better to interpret biological processes, while some others are still inconsistent with observations.Cytokinesis, as a complicated biological process, appears the nature of biological conservatism and cell-specific diversity.In this article, cortical ingression during early cytokinesis will be discussed.