This thesis aims to analyze and simulate the operation of a hydraulic motor within a hydrostatic transmission, a system widely used in industrial and mobile applications for its efficiency and versatility. By utilizing advanced simulation software like Simcenter Amesim, the main components of the transmission have been modeled. The study has been focused in particular on the motor control systems, studying the performance of the hydrostatic transmission analyzing the main parameters. The study starts with a general introduction about the hydrostatic transmissions and then continues with a brief general description of hydraulic motors. Then the specific hydraulic motor used for this activity has been analyzed in detail, with particular attention to control system.