Abstract: Plant LTR（long terminal repeat） retrotransposons have the characteristics of universality, high copy number, high heterogeneity and insertion polymorphism, which are suitable for the development of mole-cular markers. In this study, the reverse transcriptase gene sequences of Ty3-gypsy-like retrotransposons were acquired from the genome of cultivated peanut（Arachis hypogaea）, and their characteristics and differences were analyzed, which will lay a foundation for the development of LTR retrotransposons based molecular markers. A pair of degenerate primers were designed according to the conservative region of reverse trans-criptase gene of Ty3-gypsy-like retrotransposons. Then the genomic DNA of cultivated peanut variety ‘Guihua1026’ was used for amplification. After that the target band was recovered, cloned and sequenced, the obtained sequences were analyzed by bioinformatics. Finally, twenty-seven reverse transcriptase gene sequences were obtained successfully. All gene sequences were 432 bp. The proportion of AT content ranged from 55.32% to 66.90%. The ratio of AT to GC ranged from 1.24 to 2.02. The similarity of nucleotide sequences ranged from 44.90% to 98.80%. These sequences existed higher heterogeneity. Twenty-se-ven gene sequences can be divided into three families by cluster analysis. FamilyⅠ was the main component. Ten of twenty-seven gene coding protein sequences showed nonsense mutations. The similarity of gene coding protein sequences was 34.50%～97.90%. These indicated that the coding protein sequences of reverse transcriptase gene existed high heterogeneity. Except for AhRT2-4, the conserved motifs of the protein sequences encoded by the reverse transcriptase gene sequences of Ty3-gypsy-like retrotransposons are completely identical. The phylogenetic tree was constructed from the amino acid sequences of reverse transcriptase gene of Ty3-gypsy-like retrotransposons in cultivated peanut and some other plant species. The phylogenetic tree showed that all sequences were classified into six categories. Among them, Class Ⅰ contains 19 other plant species and 1 cultivated peanut sequences, and Class Ⅱ contains 8 other plant species and 7 cultivated peanut sequences. The results showed that the reverse transcriptase sequences of cultivated peanut were highly conservative. At the same time, the reverse transcriptase gene coding protein sequences of cultivated peanut is closely related to Vigna radiata,Ziziphus jujuba,Cucumis sativus,Elaeis guineensis and Hylocereus undatus. It also indicated that there may be horizontal transmission of Ty3-gypsy-like retrotransposons between them. Four Ty3-gypsy-like retrotransposons from cultivated peanut with transcriptional activity were found by aligning with peanut EST database. The reverse transcriptase gene sequences obtained in this study will lay a foundation for the development and utilization of Ty3-gypsy-like retrotransposons based molecular markers in cultivated peanut and peanut molecular breeding.