Abstract: [Objective] The expression of DNA damage repair gene under salt stress is helpful to reveal the relationship between DNA damage repair and salt tolerance of halophyte.[Method]According to the transcriptome of Halostachys caspica under salt stress,a DNA damage repair gene DNA polymerase lambda(HcDNA pol λ)was cloned from Halostachys caspica by RACE.[Result]Sequence analysis indicated that HcDNA pol λ contained an open reading frame of 1,335 bp,which encodes 444 amino acids.Conserved domain analysis showed that HcDNA pol λ was the number of DNA polymerase X family,and phylogenetic tree analysis indicated that HcDNA pol λ was an independent branch,which was an stable hydrophilic proteins sub-celled nuclear.Real time fluorescent quantitative PCR analysis showed that the expression of HcDNA pol λ of assimilating branches gradually up-regulated with the increase of NaCl concentration.At 300 mmol/L NaCl treatments,the expression levels of HcDNA pol λ were increased 3 fold and 5 fold for 7 days and for 14 days,respectively.Finally,at 700 mmol/L NaCl treatment for 14 days,the expression levels of HcDNA pol λ increased 20 fold and reached the peak.[Conclusion]The expression of HcDNA pol λ gene could be induced by salt stress.