In this proposal, we present a global sensitivity analysis method applied to the study of wave propagation occurring in a poroelastic material [Saltelli et al, 2008]. The global aim is to get relevant information in the investigation of the most influential poroelastic parameters. A sensitivity analysis allows to quantify the impact of the input parameter uncertainties on the mechanical model outputs. The analysis is based on the calculation of the Sobol indices or the partial variances that quantify the influence of each independent parameters, but also the possible interactions between these parameters, on the simulated pore pressure or solid displacement fields. The Extended FAST method is handled in combination with an efficient forward solution. The configuration under study concerns a fluid overlying a poroelastic two-dimensional halfspace ground submitted to a transient excitation [Lefeuve-Mesgouez et al, 2012]. A line source emits cylindrical waves. The problem is first solved analytically with the stiffness matrix method, to get a forward solution [Mesgouez et al, 2009]. Since the global sensitivity analysis is based on the repetition of numerous forward problems, these ones have to be efficient from the numerical point of view. Excitation type and receiver locations concern laboratory experiment simulations, of typical distance about 1 meter. A 10% uniform distribution of uncertainties has been taken into account. The same kind of approach can be applied in civil engineering, aquifer or soil auscultation, or biomechanics, involving larger typical dimensions or other uncertainty distributions. Moreover, this approach is part of a broader methodology that aims at constructing an inversion procedure involving only the parameters of interest. Four influential parameters have been identified in the specific studied configuration, rho(S), mu, phi and K-F. The methodology is generic but the results are linked to the characteristics of the problem under study.