Nano is widely recognized as the most popular technology term in the 21st century, since it can be found everywhere in our daily lives. As the scaling of materials becomes smaller, the identification of nano-structure technology is also improving. Scientists are acquiring more precise identification on the structure of materials, thanks to the invention of the optical microscopy in 17th century and scanning probe microscopy & electron microscopy & Raman spectroscopy in the end of the 20th century. The two-dimensional layered nano-materials is especially the main focus of researches in recent years, these layered materials, such as graphene, molybdenum disulfide and MOOH, are proven to have great potential in optoelectronic or energy applications.