The human hand itself is a very good example of how to implement a complex system capable to fulfill various tasks using a combination of mechanisms, sensors and controls. To create a functional and adjustable artificial human hand one needs to conceive the architecture of the system, as well as the model of its motion functions. Unfortunately, the human hand is very difficult to be modeled, because of its kinematical chains submitted to motion constraints. This is the reason why the researchers all over the world give a lot of attention to modeling process of the human hand. Following this trend, the present paper shows the complete modeling process of the human hand which leads to a reliable model of a human hand prosthesis.