[en] The behaviour of structural elements of nuclear power plants with PWR type reactors has been investigated, considering the pressure fluctuation of circulating cooling water as generating force. Causes of structural element vibrations have been analyzed, and methods of measurements and of measured data evaluation have been treated. Experiences gained by vibration measurements carried out in different power plants in other countries have been presented. A proposal has been made for measurements in the primary cooling circuits of Paks Atomic Station during installation and normal operation to make the vibration state analysis of structural elements possible. (H.E.)