Wind turbine blades are subjected to wind pressure distribution that depends on the external environment and inertial loads from their rotational velocity, acceleration and the turbine control (start-up, power production, normal shutdown, emergency shutdown, etc). In order to simulate the effect of these loads in the wind turbine blade some numerical tools are used. They are based on multiphysics simulation joining aerodynamics, hydrodynamics, control and electrical system and structural dynamics models. That enable a coupled nonlinear aero-hydro-servo-elastic simulation in the time domain using multibody 1D beam finite element model (FEM). However, when we are interested in a detailed analysis of the blade, a shell FEM with applied 3D loads must be used to obtain buckling and/or fatigue analysis. Thus, the loads estimated by 1D beam FEM simulations are transformed into a equivalent 3D pressure distributed loads for the shell FEM. Depending on how the loads are applied to the shell model, some simple methods can introduce numerical stress concentration. But other, more complex methods can have a better distribution of the stress. In the literature, it can be founded several ways to transfer the loads, called load application method (LAM), changing the way, how the loads are applied in the shell FEM. Some LAM consist in: Applying the loads directly using rigid body elements at different sections of the blade, applying nodal forces per sections of the blade following a physical distribution or creating a distributed load pressure and acceleration field for the whole blade. Each of these LAM differs in the stress distribution and displacement response of the blade. And their objective is to replicate the same behavior as the one produced by the 1D beam simulations. However, in the context of the structural reliability analysis or optimization of the wind turbine blade, the suitable method should be selected with respect to his sensitivity produced by uncertain in the LAM input parameters. This study present, a sensitivity analysis using a screening method of different LAM for shell FEM, with respect to uncertain input parameters as applied loads and material properties regarding as output tip displacement and maximum stress.