Abstract: 【Objective】 To study the effect of GbD27-6 gene on branch and lateral branch growth of sea island cotton. This study provides a basic theory for further understanding the role of GbD27 gene in intracellular transport and its participation in epidermal cell processes during fiber development. 【Methods】 In this study, the key gene GbD27-6 in the synthesis pathway of Strigolactones (SLs) was cloned from the fibrous material of Gossypium barbadense L. Pimas-7 15 d, and the expression level of GbD27-6 was analyzed by using the bioinformatics website and qRT-PCR. 【Results】 GbD27-6 gene 816 bp encoded 271 amino acid protein, molecular formula is was C₁₃₃₅H₂₁₃₄N₃₅₀O₃₈₉S₂₄, molecular weight is was about 30.081 18 kDa, isoelectric point is was 8.40, it which belonged to DUF4033 superfamily protein and was unstable hydrophobic protein. The results of subcellular localization showed that GbD27-6 gene was located on cell membrane. Real -time fluorescence quantitative analysis showed that GbD27-6 gene was expressed in petal bracts and anthers of Gossypium barbadense L. and the expression level was the highest in bracts and the lowest in petals. The expression level was the highest on the 20th day of fiber development and the lowest on the 10th day of fiber development. 【Conclusion】 The findings showed that GbD27-6 gene was differentially expressed in fibers.