A polypeptide is provided specifically binding to CD34 molecule and use thereof, the polypeptide is selected from at least one of polypeptide 17 and polypeptide 19, amino acid sequences of the polypeptide 17 and the polypeptide 19 are as shown in SEQ ID NO: 1 and SEQ ID NO: 2 in sequence listing. The polypeptide provided by the present application can specifically bind to CD34, and can be produced by artificial synthesis or genetic engineering method. Compared with antibody, the polypeptide provided by the present invention has characteristics such as low molecular weight, easy preparation and less immunological rejection and it has little toxic side-effects, its binding to the CD34+ cell wont obviously kill the target cell and inhibit its proliferation. The polypeptide provided by the present invention can be used as markers for CD34 positive expression cells, and also can be used as substitute of immunofluorescence CD34 antibody.
