There are a number of materials discovered so far in the world. Their charecterisation and synthesis gives the result which is not so feasible although many of the materials have been successfully extracted with the most purity. Among them one of the materials is carbon nanotube. Nanotechnology works with materials and ranges from extensions of conventional device physics to completely new approaches. In this paper, ahead to CVD technique for the purification, arc discharge method and other purification methods are discussed where purity of the SWCNTs synthesized by arc discharge has been reported to be 80% by volume.