The thesis work activity talks about the virtual seat modelling and the evaluation of the most sensitive parameters useful to validate the virtual seat with respect to the experimental one and then predict and evaluate the comfort inside the vehicle. Fist of all, it has been necessary to understand how the vibrations influence the human body in contact with the seat and in which way they are experimentally evaluated, in order to acquire also the main numerical seat and human parameters values which have to be inserted into the input file of the virtual model. Then, the virtual modelling part has been analysed describing all the models proposed from the past up to now and then focusing on the one used, implemented and tuned during this activity and initially furnished by the CRF.