In this study,the strong drought-resistant cotton variety ‘KK1543’ was used as the material.RT-PCR method was used to clone a HSP70 gene,a gene coding for GhHSP70 was isolated from cotton (Gossypium hirsutum L.).The open reading frame was 1 997 bp,encoding 648 amino acid residues with a predicted molecular mass of 70.94 kDa and a basic isoelectric point of 4.83.Homology analysis and phylogenetic tree analysis founded that GhHSP70 shared 96.4% amino acid identity with the HSP70 from Populus trichocarpa,and GhHSP70 protein is close to PtHSP70.An expression vector pGEX-4T-1-GhHSP70 was constructed.Then,the recombinant plasmid was transformed into Escherichia coli.The SDS-PAGE results displayed that the expressed protein was consistent with the anticipated size.The expressed protein quantity induced by 0.2 mmol/L IPTG treatment for 2 h at 37 ℃ is the highest.This study provide a fundamental condition supporting research on function of GhHSP70 gene.