Abstract: Objective To screen the clenbuterol(CLB)humanized single-chain variable region(ScFv)antibody for the study of rapid detection kit.Methods Sixty anti-CLB clones were randomly selected from the phage single-chain variable region(ScFv)antibody libary through adsorbtion-elution-amplification procedures with phage display technology.The immunity of the clones was tested with enzyme-linked immunosorbent assay(ELISA)and cross-reaction suppression test and clones with strong positive immune activity were select.The plasmids from the selected humanan tibody positive bacteri-ophage were identified with Sfi I/Not I enzyme digestion and subcloned into pCANAB 5E vector and transfered into E.coli XL1-Blue.DNA sequences of the bacteriophage selected and encoding sequences of CLBS cFv were analyzed.Results Based on the results of repeated ELISA tests and cross-reaction suppression test one positive clone was identified with new antibody fragment gene sequence of 750 bp and a GenBank registration number EU 681272.Conclusion An initial CLB of the anti-ScFv antibody was acquired with phage display technology and the experiment laid a basis for further study.