Hydrostatic drive systems are the most usable systems that are applicable in municipal vehicle. But when this system used, it is so difficult to control the vehicle and also the operator must know the way of controlling the machine, the application of motor can be said as a reason of that. Because it produces the power of hydraulics components, and the power of vehicle, too. And also machine itself can not go on the best condition of motor and hydraulics components. In this thesis the procedure that those enormous companies are dealing with and the design of smart drive systems for this kind of vehicles will be seen. The aim of this thesis is to design the best condition of drive system that of internal combustion motor, variable displacement pump and also the hydro motor. First of all the mathematical model of the internal combustion motor, variable displacement pump, must be go in the best condition of themselves, for this aim the hydro motor and also the relationship between them are obtained and by knowing that they are completed, solving and receiving result started. This system solved for normalizing condition and it can be used for all the systems like that. Also the control of the pump needs some graphs that send messages to actuator to work in the best position that are in the result of this thesis. This work is done for constant power and DA-controller and also if there is any other control function the simulation that prepared in MATLAB can be solved and the result would be obtained from. Another point that can be said is that it would satisfy the needs of operator decision like increasing the speed of vehicle with pushing pedal and changing the mode of traveling and also smoothly changing in the condition of motor. At last different control ideas like constant power and DA-controller that produced by enormous company are simulated and for new concept that means minimizing the fuel consumption the simulation is done and the result are compared with each other. These controlling functions send messages to actuator to control the swash plate of pump and also for new approach controlling the swash plate of pump and motor too.