EN
The paper discusses the impact of fluctuations on the development of socio-economic systems. It is analyzed the approaches to classification of fluctuations in economic systems. It is examined the role of fluctuations in the bifurcation and the adaptation mechanisms of socio-economic systems. At the point of system bifurcation even the slightest fluctuations caused by random circumstances can dramatically change the direction of future development. In redesigning the system to a different level of sustainability it is the fluctuations that play the role of ensuring multi-variability of development.