Abstract: An Eulerian two-phase method was presented to predict water droplets impingement for three-dimensional complex surfaces such as multi-element airfoil and engine inlet under icing conditions.The air-droplet two-phase flow was considered one-way coupled,and the airflow field was solved independently from the Euler or Navier-Stokes(N-S) equations.A treatment of boundary conditions of the droplet phase at the impingement surfaces was given.An adaptive numerical diffusion model was proposed to avoid divergence in higher order simulations caused by the singularity of droplet volume fraction in localized regions.Validation cases were performed for typical two or three dimensional bodies,including a cylinder,a MS(1)-0317 airfoil,a sphere,a multi-element airfoil and an engine inlet.Cases with droplet sizes in certain distribution were also calculated.In comparison with published experimental results,the present computational method is accurate and effective,and applicable to three-dimensional complex surfaces.