Recombinant Anti-FGFR1 x Anti-KLB Bispecific Antibody (Tandem scFv) is designed to be expressed as a scFv from an anti-FGFR1 antibody variable domains fused with a scFv from an anti-KLB antibody variable domains. It contains a His-tag at the C/N terminus for affinity purification. The BsAb exits as monomer in reducing and non-reducing conditions. This BsAb can bind two factors simultaneously and act as mimetic hormone (FGF21) . It is designed for the research of Type 2 diabetes therapy.