The present invention provides Relaxin fusion polypeptides with extended half-life. Thereby, the half-life extending parts are either the Fc moiety of the human IgG2 or of the human IgG4. Furthermore, the invention provides nucleic acid sequences encoding the foregoing fusion polypeptides, vectors containing the same, pharmaceutical compositions and medical use of such fusion polypeptides本發明係提供具有延長半衰期之鬆弛素(Relaxin)融合多肽。其中,半衰期延長部分為人類IgG2或人類IgG4之Fc部份。再者,本發明係提供編碼前述融合多肽之核酸序列、含有彼等之載體、醫藥組成物及此融合多肽之醫療用途。