ABSTRACT: Suffusion process corresponds to the coupled processes of detachment-transport-filtration of the soil’s fine fraction within the voids between the coarse fraction. Because of the great length of earth structures and because of the heterogeneities of soils, it is very difficult to characterize the suffusion susceptibility of soils all along the earth structures. So, a statistical analysis can be performed in order to optimize the experimental campaign. By using a specific triaxial erodimeter, an experimental program was setup to study suffusion susceptibility of thirty two specimens. The suffusion susceptibility is determined by the erosion resistance index. Ten physical parameters are determined and a statistical analysis is performed in order to identify the main parameters for a correlation with erosion resistance index. The multivariate statistical analysis leads to an expression of the erosion resistance index as a function of eight physical parameters, and by distinguishing the gap-graded and widely-graded soils, another new correlation is obtained with five physical parameters.