A Study to Assess the Pharmacokinetics and Safety of Recombinant Human Murine Chimeric Anti CD20 Monoclonal Antibody Injection (IBI301) Compared to Rituximab Injection in CD20 Positive B Cell Lymphoma Patients

Inclusion Criteria: 1. CD20-positive B-cell lymphoma. 2. 18 years to 65 years. 3. Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1. 4. Signed an informed consent. 5. Obtained CR (complete remission) or CRu (uncertain complete remission) after the prior therapy. Exclusion Criteria: 1. Participation in another interventional clinical trial in the past 28 days. 2. Known allergic reactions against monoclonal antibody or rituximab. 3. Rituximab and other anti-CD20 monoclonal antibody used in the past 4 months. 4. Blood concentration of Rituximab\>24ug/ml. 5. HIV positive patients. 6. HCV antigen and antibody positive. 7. Acute and chronic hepatitis B virus infection.