We develop and evaluate a novel 3D computational bone framework, which is capable of enabling quantitative assessment of bone micro-architecture, bone mineral density and fracture risks. Our model for bone mineral is developed and its parameters are estimated from imaging data obtained with dual energy x-ray absorptiometry and x-ray imaging methods. Using these parameters, we propose a proper 3D microstructure bone model. The research starts by developing a spatio-temporal 3D microstructure bone model using Voronoi tessellation. Then, we simulate and analyze the architecture of human normal bone network and osteoporotic bone network with edge pruning process in an appropriate ratio. Finally, we design several measurements to analyze Bone Mineral Density (BMD) and bone strength based on our model. The validation results clearly demonstrate our 3D Microstructure Bone Model is robust to reflect the properties of bone in the real world.