Chidamide With R-CHOP Regimen for DLBCL Patients

Inclusion Criteria: 1. Diagnosed as diffuse large B-cell Lymphoma with positive CD20 results; 2. Age between 18 to 75 years old; 3. World health organization-Eastern Cooperative Oncology Group Performance Status (ECOG) 0-2; 4. No history of malignant tumors, having no tumor other than DLBCL at the time of enrollment; 5. Life expectancy no less than 6 months 6. The patient or his/her attorney would be able to provide written consent for necessary examinations or procedures; 7. IPI mark\>1. Exclusion Criteria: 1. History of autologous stem cell transplantation; 2. History of other malignant tumors, except skin basal cell carcinoma and in situ cervical cancer; 3. With uncontrolled cardiovascular/ cerebrovascular disease, coagulation disorders, connective tissue disease, severe infectious diseases; 4. Lymphoma originated in the central nervous system; 5. Left ventricular ejection fraction ≦50％ 6. Abnormal lab results in enrollment: 1. Neutrophil count: \<1.5\*109/L； 2. Platelet count \<75\*109/L； 3. AST or ALT \>2 times the upper limit of normal level，AKP and total bilirubin \>1.5 times the upper limit of normal level; 4. serum creatinine \>1.5 times the upper limit of normal level; 7. Other uncontrolled medical conditions which the investigators think might influence the results of the trial; 8. Patients with mental illnesses or other diseases that might not comply with the trial plan; 9. Women during pregnancy or lactation; 10. HIV positive patients; 11. HbsAg (+) patients with HBV DNA(+), can be enrolled only when his/her HBV DNA turns negative; patients with HBsAg(-) HBcAb(+) can be enrolled only when his/her HBV DNA turns negative;