In order to elucidate the role of Sox2 in the earthworm Eisenia foetida during regeneration.，the full length cDNA of Sox2 was firstly cloned from earthworm by using rapid amplification of cDNA ends (RACE) approach. The expression level of Sox2 in different body segments (head, clitellum and tail) of mature earthworm and during tail segments regeneration at different time point was detected by quantitative real-time PCR. The data was analyzed by the method of Delta-Delta Ct. RACE results showed that the full-length of cDNA sequence is 2 354 bp (GenBank Accession number：KP637161), including 367 bp of 5'-UTR, 844 bp of 3 '-UTR and 1 143 bp ORF (Fig. 1 and 2). Phylogenetic analysis showed Sox2 in Eisenia foetida was conservative in phylogeny with other species (Fig. 3).The q-PCR results showed that the Sox2 expression transcripts were not significantly difference in head, clitellum and tail body segments (P>0.05) (Fig. 4a). The expression level of Sox2 in the tail was obviously up-regulated during regeneration, and reached the highest level at 12 h after amputation with 22 times compared with that in the beginning of amputation (Fig. 4b).These results indicated that the Sox2 gene may be associated with the regeneration in earthworm. Our research provided new evidence for further understanding of the molecular mechanisms of the regeneration.