Recombinant Anti-CCR3 x Anti-CD300 Bispecific Antibody (Fab-Fv) is designed to be expressed as two polypeptide chains. The heavy chain Fd fragment and light chain of an anti-CCR3 antibody are fused with the VL and VH domains of an anti-CD300 antibody respectively. It can form natural in vivo heterodimerization. This BsAb canreduce eosinophil signaling, inhibit bronchoalveolar lavage fluid inflammation, eosinophil, mast cell mediator release and reverse lung inflammation. It is designed for the research of Asthma therapy.