Aim To obtain the protein structure deduced from tree shrew (TS) apolipoprotein CI (apo CI) cDNA se-quence.Methods Using Chou's method modified and some related computer softs, not only TS apo CI cDNA sequence cloned in a constructed cDNA library of TS liver tissue was analyzed and compared with those of other species, but also the deduced amino acid (AA) sequence, its secondary structure and hydrophobility of the protein were determined and predicted.Results TS apo CI cDNA sequence consists of 380 nucleotides encoding an 88 AA apo CI precursor (a 26AA signal peptide and a 62 AA mature protein. The function domains of the protein were predicted to locate in two regions of 13~26 AA and 32~57 residues.The secondary structure may contain several kindsof conformations. There is an obvious hydrophobic region at the C-terminal of the amino acid sequence.Conclusion The present results shows TS apo CI is more hydrophobic and may have a stronger ability of binding lipids than human apo CI.