Disorders in regulation mechanisms of the cell cycle cause uncontrolled division of cells, which is the nature of neoplastic diseases. Cyclin-dependent kinases (CDK), enzymes of the serine-threonine protein kinase group, belong to main regulators of cell division in all eukaryotic organisms. Their indispensibility in regulation of the cell cycle and, in particular, their frequent deregulation in tumours led to active search for chemical inhibitors of CDK. Butyrolactone, flavopiridol , purines of the olomoucin type, paullons, indirubins and others inhibit the CDK, stop the cell cycle in the G1/S and G2/M transitions and show interesting anticancer effects. In the article, chemical properties, the mechanism of action and biological activity of the inhibitors are described.