This paper focuses on the influence of the crude oil characterization on minimum miscibility pressure (MMP) calculation. It is shown what kind of compounds may be lumped together in order to calculate the MMP with a good accuracy. In a first step, a selected crude oil is modeled with 37 pure compounds using the characterization procedure developed by Avaullee et al. (1997a) in which two parameters of the distillation residue are fitted on the experimental bubble points. In this context, all the experimental data (PVT, swelling test, slim tube test) are calculated with a very good accuracy. In a second step, the heavy intermediate, the middle intermediate and the light compounds are successively lumped. The influence of such lumping procedure on the calculated MMP is discussed.