ObjectiveTo observe the effects of rituximab injection, an anti-human B-lymphocyte monoclonal antibody, on eliminating the B lymphocytes from Chinese origin rhesus macaques, and to provide some experimental data for establishing B-cell-depleted animals models and better define the role of B cells in the control of pathogenic simian immunodeficiency virus (SIV) replication in future studies. MethodsTwo healthy Chinese origin rhesus monkeys were selected and infused with rituximab via the tail vein by intravenous drip. Peripheral blood, lymph nodes and duodenum biopsy samples were collected at different time points after injection. Lymphocytes were isolated from all the samples, stained and analyzed by FACS. ResultsThe B lymphocytes in peripheral blood of rhesus monkeys were completely depleted 24 hours after the rituximab infusion and lasted for 14 days, while 100% depletion in the inguinal lymph nodes and 90% depletion in the duodenal mucosa at 7 days after infusion. At the same time, CD4⁺ T and CD8⁺ T-cells in peripheral blood maintained at a stable level without significant fluctuation. ConclusionsB lymphocytes can be effectively eliminated from various tissues in Chinese origin rhesus macaques by rituximab injection in vivo.