1. Compare the efficacy of R-EPOCH and R-CHOP regimen for patients with AIDS associated CD20+ diffuse large B lymphoma; 2. Compare the safety of R-EPOCH and R-CHOP regimen for patients with AIDS associated CD20+ diffuse large B lymphoma.

Inclusion Criteria:

1. male or female aged 18-60 years old;
2. Confirmed as AIDS patients and treated with HAART;
3. Confirmed as CD20+ diffuse large B lymphoma;
4. Serum test; negative for HBV, HCV and syphilis;
5. Hematology: Absolute neutrophil count greater than or equal to 1000/mm(3); Platelet count greater than or equal to 50,000/mm(3); Hemoglobin greater than 8.0 g/dl; Lymphocyte count less than or equal to 4,000/mm(3);
6. Chemistry: Serum ALT/AST less or equal to 5 times the upper limit of normal. Serum creatinine less than or equal to 1.6 mg/dl. Total bilirubin less than or equal to 1.5 mg/dl;
7. Normal cardiac ejection fraction and no evidence of pericardial effusion as determined by an echocardiogram;
8. Negative pregnancy test for female;
9. Patients of both genders must be willing to practice birth control from the time of enrollment on this study and for four months after treatment;
10. To be able to understand and sign the Informed Consent Document with legal force.

Exclusion Criteria:

1. With acute disease, active infection, hemolytic anemia, coagulation dysfunction or diseases of the respiratory, circulation or central nervous system;
2. Patients with heart metastases, CNS metastases or cerebrospinal fluid malignant cells;
3. Women with pregnant or breastfeeding;
4. Any form of primary immunodeficiency;
5. Concurrent Systemic steroid therapy;
6. History of severe immediate hypersensitivity reaction to any of the agents used in this study;
7. History of allogeneic stem cell transplantation.

Patients with AIDS associated CD20+ diffuse large B lymphoma