Recombinant Anti-BAFF x Anti-B7RP1 Bispecific Antibody (scFv-CH1/CL) is designed to be expressed as two chains. One scFv from an anti-BAFF antibody variable domain is fused to CH1 and the other scFv from an anti-B7RP1 antibody variable domain fused to CL, or vice versa. And the CH1 and CL domains are linked covalently via a natural disulfide bond. This BsAb can bind and inactivate two ligands simultaneously. It can inhibit B cell survival and T cell costimulation. It is designed for the research of Systemic lupus erythematosus (SLE) therapy.