Carbon nanotubes, consisting of rolled graphene layer built from sp2 units, have attracted the imagination of scientists as ideal macromolecules and their unusual physical and chemical properties make them useful in the fabrication of nanocomposites, nano-electronic devices and sensors etc. In this account, the current status and prospect of carbon nanotubes is described with a special emphasis on the safety issue of carbon nanotubes. Even though many challenges to be solved remain, extensive and intensive efforts in both academy and industry will clear out those problems soon and finally enable carbon nanotubes to play a key innovative material of 21st century in numerous industrial processes.

• Morinobu Endo(Department. of Electrical and Electronic Engineering, Faculty of Engineering, Institute of Carbon Science and Technology, Shinshu University)
• Yoong-Ahm Kim(Department. of Electrical and Electronic Engineering, Faculty of Engineering)
• Takuya Hayashi(Department. of Electrical and Electronic Engineering, Faculty of Engineering)