Based on the similarity analysis between the spherical and nonspherical particle packings, a mathematical model, modified fi om the previous linear packing model for spherical particles, is proposed for predicting the porosity of nonspherical particle mixtures. The background for this development is discussed in detail. The applicability of the proposed model is validated by the good agreement between the measured and calculated results for various packing systems including binary, ternary, and multicomponent packing of spherical spherical and/or nonspherical particles.