The cell cycle is a successive process between two mitosis divisions. During these courses, the cellular genetic materials, for instance DNA, are equally assigned to two daughter cells after replication. Each cell is endowed with its own share of the parental chromosomes. The schedule of events in cell cycle happens in the presence of regularity, precision and perfect temporal and spatial restriction. CDKs, cyclins and cdc are essentially key regulators of three families in control of cell cycle. The discovery of these regulators has important values on both basic research and applied biotechnology.