Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disorder.Mutations in the Cu,Zn-superoxide dismutase(SOD1)gene cause ALS by an unknown gain-of-function mechanism.Current researches show that diminishing SOD1 mutation enzymatic activity does not account for motor neuron lose in ALS,while direct toxicity of variant SOD1 protein or aggregation of SOD1 protein may impart cell function and cause motor neuron death.Though motor neuron death is selective,other cells also participate in this course.The author reviewed recent advances in the relationship between mutant SOD1 and Amyotrophic Lateral Sclerosis.