[en] The compression of elastic nanoparticles by two rigid planes is analyzed in the present paper. Through a finite element approach with the incorporation of surface energy, we calculate the elastic field of nanoparticles and obtain the explicit expressions for contact radius and indent depth with respect to the compressive load. It is found that when the contact radius is comparable with the ratio of surface energy density to elastic modulus, surface effect significantly affects the elastic field and the overall compressive response of nanoparticles. This study provides an effective tool to analyze the elastic deformation of nanoparticles, and is helpful to measure their elastic properties through compression. (paper)