OBJECTIVE: To summarize and analyze the factors and theories related to the attack of motor neuron disease, and comprehensively investigate the pathogenesis of motor neuron disease. DATA SOURCES: A search of Pubmed database was undertaken to identify articles about motor neuron disease published in English from January 1994 to June 2006 by using the keywords of “neurodegenerative diseases”. Other literatures were collected by retrieving specific journals and articles. STUDY SELECTION: The data were checked primarily, articles related to the pathogenesis of motor neuron disease were involved, and those obviously irrelated to the articles were excluded. DATA EXTRACTION: Totally 54 articles were collected, 30 of them were involved, and the other 24 were excluded. DATA SYNTHESIS: The pathogenesis of motor neuron disease has multiple factors, and the present related theories included free radical oxidation, excitotoxicity, genetic and immune factors, lack of neurotrophic factor, injury of neurofilament, etc. The studies mainly come from transgenic animal models, cell culture in vitro and patients with familial motor neuron disease, but there are still many restrictions and disadvantages. CONCLUSION: It is necessary to try to find whether there is internal association among different mechanisms, comprehensively investigate the pathogenesis of motor neuron diseases, in order to provide reliable evidence for the clinical treatment. OBJECTIVE: To summarize and analyze the factors and theories related to the attack of motor neuron disease, and comprehensively investigate the pathogenesis of motor neuron disease. DATA SOURCES: A search of Pubmed database was undertaken to identify articles about motor neuron disease published in English from January 1994 to June 2006 by using the keywords of “neurodegenerative diseases ”. Other literatures were collected by retrieving specific journals and articles. STUDY SELECTION: The data were checked primarily, articles related to the pathogenesis of motor neuron disease were involved, and those are irrelated to the articles were excluded. DATA EXTRACTION: Totally 54 articles were collected, 30 of them were involved, and the other 24 were excluded. DATA SYNTHESIS: The pathogenesis of motor neuron disease has multiple factors, and the present related dynamica included free radical oxidation, excitotoxicity, genetic and immune factors, lack of neurotrophic factor, injury of neurofilament, etc. The studies mainly come from transgenic animal models, cell culture in vitro and patients with familial motor neuron disease, but there are still many restrictions and disadvantages. CONCLUSION: It is necessary to try to find whether there is internal association among different mechanisms, comprehensively investigate the pathogenesis of motor neuron diseases, in order to provide reliable evidence for the clinical treatment.