To ascertain the risk factors of AA in ZheJiang Province of China at the moment, especially the comprehensive multiple factors risks. The author conducted a case-control research included 338 AA cases and 1464 controls. Subjects were surveyed using same standard questionnaire including personal data, past histories of diseases, family history and histories of occupational and daily exposure to harmful substances. Single and multiple Logistic regression analyses were made using SPSS17.0 on the dates to study potential factors in the development of AA.

Inclusion Criteria:

• All the patients of AA group met a AA diagnostic criteria；The control group were chosen from other departments who were under acute infection (such as pneumonia), acute abdominal emergency (such as appendicitis), cataract surgery;
• 1-65 years old, male or female;
• Sign the informed consent.

Exclusion Criteria:

• With myelodysplastic syndrome, leukaemia, multiple myeloma,megaloblastic anaemia, paroxysmal sleep hemoglobinuria disease blood disease, etc.
• History of tumor, radiation or chemotherapy, once accept the immunological therapy, autoimmune diseases or allergic disease patients;
• Patients with neurological diseases.

All the patients of AA group met a AA diagnostic criteria；The control group were chosen from other departments who were under acute infection (such as pneumonia), acute abdominal emergency (such as appendicitis), cataract surgery; All cases had no history of tumor and radiation and chemotherapy, without receiving the immunological therapy; the control group cases without hematological diseases, autoimmune diseases, Fanconi anemia, congenital diseases, etc.