The door closing effort is one of the first impressions to customer's mind about the engineering and quality of the vehicle. The door closing force and the minimum door closing speed are two important characteristics for evaluation. But we can obtain these two indices only by experiments and/or subjective assessments. To predict the door closing effort by the simulation method during the design phase, a finite element analysis model is established. The compression load deflection behavior of seals is converted to the parameters of constitutive model of seals by the parameters identification method. Then, the seal resistance force and the minimum door closing speed are calculated. The later correlates very well with the experiment data.