The precise design and fabrication of biomaterial scaffolds is necessary to provide a systematic study for bone tissue engineering.Biomaterial scaffolds should have sufficient stiffness and large porosity.These two goals generally contradict since larger porosity result in lower mechanical properties.This paper is to seek the microstructure of maximum stiffness with the constraint of volume fraction by topology optimization method.Algorithms and programs were built to obtain 2D and 3D optimized microstructure and transfer the solution to CAD models of STL format in MATLAB.Ti scaffolds with 30% volume fraction were fabricated using a Selective Laser Melting (SLM) technology.The architecture and pore shape of microstructure were relatively precise reproduced and the minimun mean pore size was 231μm.The accurate fabrication of intricate microstructure has verified that the SLM process is suitable for fabrication of metallic biomaterial scaffolds.