During last y years a renewed interest in high hydrostatic pressure (HHP) is observed particularly in food and pharmaceutical industry where is uses for preservation and sterilization of products. Pressure is a physical factor affecting conformation of biological macromolecules and influencing chemical reactions without introduction of any additional agents, e.g. salts. So it is a considerable factor in basic research, which enables analysis of the mechanism of conformational changes of nucleic acids, proteins and lipids as well as interactions between molecules. Detailed analysis of these processes is valuable not only from cognitive point of view but it has very important practical aspect. HHP become wider and wider used for inactivation of bacteria so recognition of its influence on entire cell is important for safety of consumers and patients.