Mecobalamin as vitamin B12 derivatives, should be called “methyl vitamin B12″ according to the chemical structure of name, the functional groups of methylation can be involved in the biochemical process of methyl transfer activity, promoting to nucleic acid of nerve tissue, the metabolism of protein and fat, , can stimulate the synthesis of lecithin Schwann cells, repairing the damaged myelin, improving nerve conduction velocity; directly into nerve cells, and stimulating axon regeneration of damaged area; stimulating protein synthesis in nerve cells and enhanced synthetic metabolism of axons to prevent axonal degeneration; involved in nucleic acid synthesis, promoted hematopoietic function. The treatment is clinically used in diabetic neuropathy, long-term use of macrovascular complications of diabetes are the curative effect.