In the paper model of macroeconomic turnover and its possibilities for investments modelling are shown. The model consists from four blocks: in the first the theoretical model is described. In the second the model is reflected in accordance with the requirements of system dynamics method, there are shown included influences intercommunications and equalizations. The third block examines demand and supply model for capital and investments. Fourth part complements previous parts, describes additional indexes. The method is offered for using both in forecasting and in teaching.