Primary objective of the study is to compare the efficacy and safety of CDOP versus CHOP for newly diagnosed peripheral T-cell lymphoma (PTCL).

This is a open-label, multi-center, randomized, non-inferiority study to compare efficacy and safety of CDOP with standard CHOP regimen in patients with previously untreated PTCL. Study subjects are patients with histologically proven newly diagnosed PTCL. Patients are randomized 1:1 to receive either cyclophosphamide, pegylated liposomal doxorubicin, vincristine and prednisone (CDOP) administered in 3 week cycles for 6 cycles or cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) administered in 3 week cycles for 6 cycles.This study is divided into three phases: screening phase, treatment phase and follow-up phase. Patients will receive study drug(s) for up to 6 cycles, or until unacceptable toxicity will develop or progression or voluntary withdrawal.Adverse event of every treatment cycle will be recorded.Therapy efficacy will be evaluated after finishing 2 cycles, 4cycles and finishing 6 cycles therapy. Patients will be followed until disease progression, died or 2 years from the last patient randomized.

Inclusion Criteria:

1. Patients with histologically proven untreated peripheral T-cell lymphoma (include PTCL not otherwise specified（PTCL-NOS）, angioimmunoblastic T cell lymphoma（AITL）, anaplastic large cell lymphoma（ALCL）and other peripheral T-cell lymphoma(except NK/T cell lymphoma);
2. Males and females of 18 years of age to 75 years of age.
3. Eastern Cooperative Oncology Group (ECOG) performance status 0- 2.
4. At least 1 single size measurable lesions, CT or PET-CT scan shows more than 15mm.
5. Estimated survival time ≥ 6 months
6. Liver function: transaminases≤3×ULN，or transaminases≤3×ULN for liver metastasis，total bilirubin ≤1.5ULN，or total bilirubin ≤2.5ULN for Gilbert's syndrome
7. Renal function: serum creatinine ≤1.5×ULN or creatinine clearance ≥ 60 ml / min ( standard Cockcroft-Gault formula);
8. peripheral hemogram: WBC≥3.0×10^9/L, ANC≥1.5×10^9/L, Hb≥90g/L, PLT≥75×10^12/L.
9. Cardiac ultrasound LVEF≥55%;
10. New York Heart Association (NYHA) heart function classification is I grade;
11. sign informed consent.

Exclusion Criteria:

1. Patients with primary or secondary central nervous system lymphoma；
2. Serious heart disease, including but not limited to:

1)Significant ventricular arrhythmia or high degree atrioventricular block (Mobitz II or third degree atrioventricular block); 2) unstable angina; 3) clinically significant heart valve disease; 4) Electrocardiogram shows transmural myocardial infarction; 5) Uncontrollable hypertension; 3. interstitial pneumonia, allergic asthma or severe allergic medical history; 4.Patients with other malignancies in the past or now (except basal cell carcinoma, squamous-cell carcinoma or carcinoma in situs of cervix that has been adequately treated), 5.HIV antibody positivity; 6.Acute or chronic active hepatitis B (HBsAg positivity, HBV DNA negative acceptable), acute or chronic active hepatitis C (HCV antibody negatively acceptable; HCV antibody positivity, HCV RNA negative acceptable) 7.Pregnancy or lactation period 8.Patients with Organ transplantation 9.Patients with serious uncontroled acute infection 10.High doses of hormones are contraindicated, such as uncontrolled hyperglycemia, stomach ulcers or Mental illness, etc.

11.Patients with severe neurological or psychiatric history, including dementia or epilepsy 12.The researchers considered that patients are not suitable for the study