Abstract: The amino acid sequence information of CG13551 gene is retrieved from the database. Physicochemical analysis show that the SK₆₆ protein contains 107 amino acid residues, with a molecular weight of 11 948.3 Da and a theoretical isoelectric point of 8.96, the content of glycine (Gly) is 14.0%. Glutamic acid (Glu) and alanine (Ala) are 11.2% and 9.3%, respectively, SK₆₆ protein is a hydrophilic protein and is not a secreted protein. SK₆₆ protein does not have transmembrane domain. Protein secondary structures include 57.96% α-helix, 10.28% β-folding, β-turning and 31.78% random crimp. The evolutionary tree is mainly divided into two groups. The higher animals are divided into the first group, including human, mouse and puffer fish, while the lower animals are divided into the first group, including zebrafish and fruit fly. This is consistent with the degree of evolution of the species.