The diversities in crystalline structure and the hierarchical features of the structures in metals lead to their distinguished deformation behaviour, elastic properties, magnetic properties, electric properties, mechanical properties, etc. In the research of metallic materials, the linkage of structure-processing-property is considered as the very important principle to understand the alloys. Following this basic principle, one can further design, select and assess suitable materials for a specific application. Over the last decades, based on multi-scale understanding of the metallic materials - from metre (components) to micrometre (grains and phases) and further down to nanometre (second phases and stacking faults), a number of extraordinary metallic materials have been successfully developed and commonly applied, e.g. ultra-strong steels for automotive and aerospace applications, orthopedic medical materials, etc. This research work will present several nano-engineering concepts that offer new opportunities to design and engineer the novel metallic materials into hierarchical structures with tailored properties. The multi-scale characterization of the hierarchical features in high strength steels from atomic scale to millimetre scale will be focused. New approach that aid controlling the process of phase transformation during deformation and/or thermal treatment in the steels will be discussed.