Inclusion Criteria:  Meet the diagnostic criteria for paroxysmal nocturnal hemoglobinuria; Age ≥ 18 years old; PNH clone size of granulocytes or monocytes (CD59 or Flaer) ≥ 10%; LDH≥1.5 ULN; Accompanied by at least one PNH-related symptoms: fatigue, hemoglobinuria, abdominal pain, dyspnea, anemia symptoms, major adverse vascular events (including thrombosis), dysphagia, erectile dysfunction; Transfusion-dependent PNH patients; There are at least 6 months consecutive data of diagnosis and treatment after the data collection time point; Patients agreed to participate in the study by signing informed consent or giving oral informed consent.  Exclusion Criteria:  Patients are under the treatment of the C1/C3/C5 complement inhibitors currently or in the past; Patients have received bone marrow transplantation; platelet count <30*10 9/L or absolute neutrophil count <0.5*10 9/L; Patients have clinically significant heart, liver, or lung diseases, or have related medical history. Patients have comorbidities of rheumatoid disease, HIV infection, active HBV infection, HCV infection and other diseases that affect the body's immune function; Severe missing data in the records of diagnosis and treatment after the data collection time point; Other patients who are not suitable to participate in the study.