EN
The author reviews the method of analysis of business cycles based on statustucal information of a high frequency, i.e. monthly or quarterly time series. The review is not limited to the well-known and applied methods; some new directions of analysis as well as author's suggestions of improving the mothods used are presented. The considerations are preceded by a brief discussion of causes of economic fluctuations. In the final part of the paper a summary of results of research in economic fluctuations in Poland since 1975 is given.