The present invention discloses a functional polypeptide which is 1) a polypeptide having the amino acid sequence of SEQ ID No. 1； or 2) a polypeptide having a substitution or deletion or addition of one or several amino acids from the sequence shown in SEQ ID No. 1 that has the same or similar function. The invention also discloses the utility of the described functional polypeptide. The functional polypeptide of the present invention can significantly inhibit bleomycin-induced pulmonary fibrosis formation and has a remarkable effect of preventing and treating pulmonary fibrosis.
