Small heat shock proteins (sHSPs) are members of a diverse family of stress proteins that are important in cells to protect proteins under stressful conditions. Degenerate primers were designed based on the conservative sHSP gene sequence of other plants in the GenBank to clone the full-length cDNA of Co- sHSP gene by using RACE and RT-PCR methods in the research. Bioinformatics analysis revealed that the cDNA is 699bp in length, encoding 159 amino acids residues, the putative molecular weight is 18.08 kD and the pi is 6.20, and there are two conserved domains in the protein sequence aligned with other sHSPs. The phylogenetic investigation indicated that the relationship among the same class sHSP family was very close. Five alpha-helices and seven beta-strands were found in the second structure of Co-sHSP and its theoretical 3D structure showed an active site between Arg99 and Glu105. In order to study the function of Co-sHSP, the gene was expressed in E.coli, the result showed that Co-sHSP significantly enhanced cell survivability against heat stress.