Abstract: Neuron axonal signals play an important role in myelination of central nervous system. Myelination depends on a balance between the positive and negative neuron axonal signals. The positive signals, such as neuregulins (NRG), neuron cell adhesion molecule (NCAM), electrical activity and neurotrophins, have a function of promoting the proliferation and the myelination thickness of ensheathing glial cells, while the negative factors like the L1 protein, poly-sialic acid-neuron cell adhesion molecule (PSA-NCAM), will lead a marked decrease in myelination. Here，we mainly present some well-researched neuron axonal factors and their mechanism.

Key words: neuron axonal singnals, ensheathing glial cells, myelination, MAPK pathway, review