Selective laser melting (SLM) is a powder-based additive manufacturing (AM) process that uses high laser energy to melt powders into solid parts. It provides many benefits over conventional manufacturing methods, such as geometric freedom, tooling-free production, and customization, etc. It has already been embraced by many industries, such as biomedical and aerospace industries, etc. Although the promising prospect of its application in civil engineering, SLM technology is still at a preliminary stage for construction industry. Therefore, to enlarge the scope of the application of this technology in construction industry, some ongoing issues associated with this technology should be systematically studied or solved. Firstly, because of the unique process characteristics, the microstructure of SLM-fabricated components is often metastable and has fine grains. As a result, SLM-fabricated components usually have high tensile strength but inferior ductility. Secondly, Microstructure defects such as porosity and balling often occur in the SLM-fabricated components. Finally, high level of residual stresses can occur in the SLM-fabricated components because of the large temperature gradient and high cooling rate during processing. Accordingly, this thesis is concerned with some issues related to SLM-fabricated H13 high strength steel, beginning with investigation of initial powder characteristics and ending at mechanical properties investigation and residual stress characterization of structural components. Firstly, the powder characteristics of H13 high strength steel were investigated to better understand the laser-powder interaction during the SLM processing. Optimal SLM processing parameters were also explored for H13 high strength steel. Secondly, the mechanical properties and structural performance of additively manufactured high strength steel tubular sections were investigated at the cross-sectional level through experimental programs. Thirdly, the residual stresses were investigated by neutron diffraction method to study the effect of scanning patterns and cross-sectional geometries of hollow section. Finally, post heat treatments were utilized to improve the mechanical properties of SLM-fabricated H13 materials. Last but not least, the remaining issues and suggestions on future research on SLM- fabricated high strength steel are put forward.