Each enterprise considering its structure, requires different types of management to achieve the goals. Management of farmlands mechanized agricultural systems is one of the important factors to succeed farmers. In this research, a model was developed to select agricultural machinery fleet, particularly in multicropping systems. The Model was a linear integer optimization model for minimization of costs and performed under LP-ILP (QSB) program. Raw data for three crops of wheat, barley and potato were obtained from the Ahyai Agriculture Complex located in Hamedan city, and related analyses were performed. Finally, according to the constraints of working periods, optimal required machinery set was calculated and proposed. This optimal machinery set supplied machinery requirements of farms and also minimized machinery costs.