This issue includes selected papers from the 8th International Conference on Nanostructures, Nanomaterials and Nanoengineering 2019 (ICNNN 2019) and from 2019 International Conference on Materials Technology and Applications (ICMTA 2019), Kyoto, Japan, 11th-14th Oct, 2019 and reflects research results of materials for the biomedical application, polymers and composites, structural materials (alloys, steel and building materials), functional and special materials, carbon nanotube and graphene, nanomaterials, chemical technologies for the various applications.