Guillain-Barre syndrome (GBS) is an acute polyneuropathy characterized by progressive motor weakness of limbs with areflexia. This disease is usually triggered by an infection, which provokes immune-mediated nerve dysfunction. GBS can be subdivided into the classic acute demyelinating type, acute motor axonal neuropathy (AMAN), and acute motor and sensory axonal neuropathy (AMSAN). Classic acute demyelinating type is designated acute inflammatory demyelinating polyneuropathy (AIDP), representing the great majority of cases in Europe and North America. A mutation in the PMP22 gene was identified in a family with AIDP. AMAN is the most prevalent form in China. The incidence of AMSAN is very low. The axonal forms of GBS are caused by certain autoimmune mechanisms, due to a molecular mimicry between antecedent bacterial infection (particularly Campylobacter jejuni) and human peripheral nerve gangliosides.