The invention relates to a polypeptide and application thereof, in particular to a polypeptide for promoting liver cell proliferation and / or inhibiting liver cell apoptosis and application thereof. The amino acid sequence of the polypeptide for promoting liver cell proliferation and / or inhibiting liver cell apoptosis is selected from at least one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5 and SEQ ID NO: 6. The polypeptide disclosed by the invention has the activity of promoting liver cell proliferation and / or inhibiting liver cell apoptosis, which is equivalent to or better than that of HIP / PAP, and has the advantages of small molecular weight, easiness in synthesis, low immunogenicity and the like, so that the polypeptide disclosed by the invention has a wide application prospect.