1. Describe the distribution of ALS in mainland China, to explore the differences in the number of ALS in different times, regions and populations in order to further explore the causes affecting the distribution of ALS;
2. To investigate the cause of ALS in mainland China in the crowd disease development process and the corresponding characteristics change ;
3. To explore the effect of prognosis of ALS;

With the development of supportive measures, the natural history of ALS has changed. Researchers compared the natural history of ALS patients from 1999-2004 and 1984-1998 and found that the median survival time was significantly longer in the former than in the latter (4.32 years vs. 3.22 years) and that the disease progression was slower in the former, even after adjusting for other confounding factors. Although previous studies have provided reference for the diagnosis and treatment of ALS, the etiology of ALS is still unknown, and the relevant clinical features and natural history of ALS still lack the verification of large samples. Therefore, the research on the natural history of ALS is of great significance to further increase the understanding of ALS and provide new evidence for the diagnosis and treatment of ALS.

Inclusion Criteria:

- Patients were diagnosed with ALS recruited from all participant clinical centers.The diagnosis of ALS was made using the revised El Escorial criteria for definite, probable, lab-supported, and possible.

Exclusion Criteria:

• Decline to follow-up.

ALS patients in mainland China.