Synthetic biology has developed quickly worldwide. In this special issue, we reviewed its recent progresses in technologies and applications, these are: markerless knockout of chromosome genes in Streptomycetes spp. and in gene synthesis technology, in microbial genome reduction and modification, as well as genome minimization method based on metabolic network analysis and combinatorial optimization of synthetic biological systems. We also discussed photosynthetic cyanobacterial chassis, development in molecular genetic manipulation of solventogenic clostridiax. Protein budget: cost estimating criteria for synthetic biology, was also brought out for our attentions. On the application sites, some successful applications of synthetic biology were demonstrated, including design and construction of artificial biological systems for complex natural products biosynthesis, engineering the Saccharomyces cerevisiae for sclareol production, and engineering the xylose metabolic pathway for microbial production of bio-based chemicals.