Recombinant Anti-CCR3 x Anti-CD300 Bispecific Antibody (scFv-CH3) contains two chains. The anti-CCR3 scFv is fused to the Knob-CH3 domain via a hinge region and the same as the anti-CD300 scFv to the Hole-CH3 domain, or vice versa. The KIH CH3 domains can facilitate to form a heterodimer and this bivalent binding leads to improvement in avidity. 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.