This thesis aims at comparing two simulation softwares used for hydraulic circuit simulations. The softwares under study are Simcenter Amesim by Siemens and Simscape Fluids by Simulink. This comparison will reveal itself important in showing how effective a simulation environment like Simulink which is cheaper and more accessible could be in simulating complex automotive hydraulic circuits with respect to a more professional and expensive hydraulic simulation environment as Amesim. This comparison is done on three hydraulic circuits which are: •??Vehicle power steering unit hydraulic system. •??Hydrostatic transmission for vehicles. •??Hydraulic systems for controlling a semi-automatic gearbox. The work will start from already built Amesim models of each circuit then circuits of the same characteristics is reproduced on Simscape Fluids and a critical comparison of the results obtained on both platforms is done..