The Lipaphis erysimi (Kaltenbach) is one of the agricultural insects endangering cruciferous vegetables,and it has a rapid propagation speed and is distributed all over the world. Telomerase reverse transcriptase (TERT) is a catalytic subunit of telomerase,which not only can induce telomerase activity to affect cell aging and apoptosis,but also has other biological functions besides telomerase dependent. In order to clarify the mechanism of the telomerase reverse transcriptase (TERT) in insect growth and development,the TERT in L. erysimi (Kaltenbach) was cloned and its spatial and temporal expression was analyzed. According to the local transcriptome library,the related sequences of TERT gene of L. erysimi were screened,and the CDs sequences of TERT gene were cloned by gene amplification. The full-length sequence of the CDS region of the gene is 2 658 bp,which can encode 885 amino acid residues. Its secondary structure contains 41 alpha-helixes and 60 coiled coils. After uploading it to the NCBI,it was found that the gene has the highest homology with Diuraphis noxia,and has low homology with other species. The relative expression of TERT in different ages and tissues of L. erysimi was analyzed by real-time PCR. The results showed that the relative expression of TERT gene in the adult stage of L. erysimi was the highest,and there were significant differences with each age. The expression level of 1st instar nymph was significantly lower than that of adults,but significantly higher than that of 2nd,3rd and 4th instar nymphs. The expression level of 4th instar nymph was the lowest,but there was no significant difference with that of 2nd and 3rd instar nymphs. Subsequently,the 4th instar nymphs,which is basically mature and has the lowest expression level of TERT gene,was selected for dissection. We were able to simultaneously detect the expression of TERT gene in the head,chest and abdomen of 4th instar nymphs with the highest expression in the abdomen. These results suggest that the TERT gene plays an important role in the growth and development of L. erysimi,and the region with low similarity can be selected as the target region for gene interference or silence so as to control the major harm caused by L. erysimi in agriculture.