NOVELTY - Preparing carperitide based on Fmoc solid-liquid combined route involves making several peptide fragments using Fmoc solid synthesis; combining the fragments and cleaving from resin to form linear carperitide that is subjected to liquid phase oxidation to obtain cyclized carperitide.    USE - For preparing carperitide used to treat acute heart failure.    ADVANTAGE - The solid-liquid phase combined route for synthesizing carperitide is featured with simple operation, short synthesis period, and is eco-friendly. Using this method, synthesis of several segments is achieved at the same time, and the synthesis cycle is reduced by 2/3, the intermediate is easily purified, the cost is low, the final product has high purity, there is only little by-product, product yield is high, and is good for large-scale production of carperitide. By using this method coarse peptide liquid with purity of more than 75% and total yield of more than 25% is obtained.    DETAILED DESCRIPTION - Preparing carperitide, involves    (1) synthesizing peptide resins with completely protected side chains on a solid phase carrier through solid phase Fmoc route and cleaving from resin to obtain peptide fragments: Boc-Ser(R)-Leu-Arg(pbf)-Arg(pbf)-Ser(R)-Ser(R)-Cys(Trt)-Phe-Gly-Gly-OH (fragment A(1-10)); Fmoc-Arg(pbf)-Met-Asp(OtBu)-Arg(pbf)-Ile-Gly-OH (fragment B (11-16)); Fmoc-Ala-Gln(Trt)-Ser(R)-Gly-OH (fragment C (17-20)) and: Fmoc-Leu-Gly-OH (fragment D (21-22)); and synthesizing Fmoc-Cys(trt)-Asn(Trt)-Ser(R)-Phe-Arg(pbf)-Tyr(tBu)-Resin (fragment E) on a solid phase carrier through solid phase Fmoc route;    (2) subjecting peptide fragment (D) to coupling reaction with the peptide resin (E) to obtain a peptide resin (R1);    (3) subjecting the peptide fragment (C) to coupling reaction with (R1) to obtain a peptide resin (R2);    (4) subjecting peptide fragment (B) to a coupling reaction with (R2) to obtain a carperitide resin (R3);    (5) subjecting peptide fragment (A) to coupling reaction with (R3) to obtain a carperitide resin (R4);    (6) cleaving (R4) from resin to obtain a linear carperitide peptide;    (7) subjecting the linear carperitide peptide to liquid phase oxidation to obtain cyclized carperitide; and    (8) optionally purifying the peptide using reversed phase high pressure liquid chromatography (RP-HPLC), collecting the target peak fraction, evaporating, concentrating, and freeze drying to obtain the refined carperitide peptide.    R=tert-butyl or trityl