We have untertaken lots of research and development work in the carbon nanotubes synthesis and application since 1996. A scalable CVD method to produce high purity single-wall carbon nanotubes (SWNTs) and multi-wall carbon nanotubes (MWNTs) with various diameters and narrow diameter distribution has been developed. The technology for producing 5kg 20-40nm MWNTs per day was evaluated as an advanced technology in the world by CAS scientists. We can produce 1.5kg SWNTs per day and 10kg MWNTs with 8-15nm in diameter every day. The production facilities can be enlarged easily. And MWNTs with purity can reach to more than 98wt% max.