Objective To create a geometrical and mechanical accurate patient-specific 3D FE model of whole pelvis, and based on which simulate a common case of sacroiliac joint fracture.M ethods The individual geometry of the sacral and hip bones were well reproduced by CT data and then an ad hoc biomechanical semi-automatic mesh generator, which could take the advantage of pairs of frame curves capturing the bone shape feature, was employed to generate regular FE mesh of the pevis model. The sacroiliac joint related end plates, cartilages, and contact surfaces, as well as several important ligaments and the interpubic disc were finally reconstucted to consummate the whole model.R esults A realistic individual FE model of whole pelvis was constructed, including the cortical and trabecular bone of the sacral and hip bones, all anatomical features of sacroiliac joint: end plates, cartilages, and contact surfaces having friction, as well as interosseous sacroiliac ligament, anterior sacroiliac ligament, posterior sacroiliac ligament, sacrospinous ligament, sacrotuberous ligament, superior pubic ligament, arcuate pubic ligament, and the interpubic disc. The simulation results from this normal whole model undering loading as well as the case of sacroiliac joint fracture were closely correlated with published results of experimental biomechanics.C onclusion By a specifically designed biomechanical modeling tool, an accurate individual FE model of whole pelvis including almost all complex anatomical features was generated, which could be used as the foundation for biomechanical analysis of the whole pelvis structure.