Abstract: Using a RT-PCR method,the partial cDNA sequences of heat shock protein 70 genes from three populations (Hainan,Hebei and Liaoning of China) of migratory locusts,Locusta migratoria L.were cloned and then analyzed.Under predetermined optimal reaction conditions,one fragment of 604 bp was amplified from eggs of Hebei locust population with a pair of degenerate primers (GenBank accession No.AY299637),and deduced amino acid sequence contains 201 residues.Analyzed results show that there is high homology of amino acid sequence between the migratory locust and other insects,and nucleotide sequence identity among three locust populations is 98.75% in this fragment.Therefore,it is suggested that difference of cold hardiness between different locust populations might be connected with the induced expression of heat shock protein 70,but not the cDNA sequence divergence.