As a variety of cytokines receptors,epidermal growth factor receptor(EGFR)plays an important role in cell proliferation,migration and differentiation.It was not only involved in regulating growth and development in tissues,but also in the wound healing.In the present study,cDNA full-length sequence of the EGFR gene was cloned in coelomocytes of Apostichopus japonicus, by using 3′ RACE and 5′ RACE,and the sequence and structural analysis of the EGFR gene by using bioinformatics methods.The results showed that the cDNA length was 3 826 bp,including the 821 bp of the 5′-UTR and 281 bp of the 3′-UTR.The open reading frame was 2 724 bp,which could encode 907 amino acids.The deduced amino acid sequence of 55-184aa and 365-487aa was L1 and L2 receptor domain of the EGFR gene.The CR1 and CR2 cysteine-rich regions,which were transmembrane glycoprotein,were located in the 203-344aa and 503-823aa regions.Identity rates of deduced amino acid sequence of EGFR with those of known species were subjected to BlastP searching in NCBI.Results showed that the structure of EGFR gene in the study was similar to that of other species EGFR gene,and the amino acid sequence of EGFR gene of A.japonicus was 49% in similarity and 34% in homology with EGFR of Drosophila melanogaster and 47% in similarity and 34% in homology with EGFR of Danio rerio and 49% in similarity and 31% in homology with EGFR of Lymnaea stagnalis. All results indicate that the EGFR gene of A.japonicus detected in this study is one of the EGFR family members.Based on the results above,expression of EGFR in different tissues by relative quantitative RT-PCR, the internal standard gene was Cytb. The result showed EGFR expresses in every tissue of A. japonicus, especially higher in coelomocyte and epidermis,which was 143.87 and 51.67 times of the respiratory tree,and the difference was significant to other tissues (P<0.05).The expression of intestine and longitudinal muscle was low,only 10.82 times and 4.47 times of respiratory tree,and the difference was not significant (P>0.05).These results indicate that the EGFR plays an important role in cell growth and tissue regeneration of A. japonicus.