It is essential to develop a cost effective fleet of machinery for the present day various standard sizes of plants. In the case of the small units it is essential to develop equipment and cost saving mechanical solutions, but there is also demand for the building up of systems of machinery with modern, cutting edge technology and profit improving attributes for the middle-sized farms, which more favourable specific cost level. The changing and modernising of the Hungarian fleets of machinery, the majority of which is obsolete is unavoidable. Farmers working from different amounts of capital on farms, which provide different levels of mechanical development potential, have to develop mechanisation solutions using the wide range of types and price range of the power and work machinery. Taking into consideration the current partitioned structure of the farms the goal was established to determine that in the case of the different branches of plant production on small and middle-sized farms which combination of fleet of machinery can be used effectively.