The diploma thesis deals with the modelling of seasonal time series and its illustrations on a real time series. The thesis presents both regression methods, including dummy variables, Fourier terms and TBATS as well as methods used mostly for predictions such as exponential smoothing and ARIMA models. The application of the methods was done in R using the seasonal time series of sales of golf accessories. The aim of the thesis is to compile the methods used for the analysis of seasonal time series, apply these methods to the empirical time series and evaluate the quality of the prediction of individual methods.Diplomová práce se zabývá modelováním sezónních časových řad a jeho ilustrací na reálné časové řadě. V práci jsou představeny jak r...