(Strongylocentrotus intermedius) is a species of commercial and ecological significance, and as a economic species, sea urchin has been demanded steadily in Europe and Southeastern area for a long time. Recent studies focused on the development of its genomic resources, which is a key step towards further investigation, identification of gene and gene networks involved in its economic characters. Efforts have been focused on genes that can affect expression of important economic traits, such as growth and nutritional traits related genes. In this study, a cDNA library of sea urchin has been constructed from gonad using Gubler-Hoffman cDNA library technique. Total RNA was extracted from the grounded frozen powder of gonad tissue by using acid-guanidine- phenol-chloroform (AGPC). Poly(A)⁺ RNA was isolated and purified by oligo(dT)₁₈ anchor primer containing site. Both ends of the newly generated and polished double-stranded (ds) cDNA were attached by R . The short cDNA (<400 bp) was removed by Spin Column. PFU/mL colony forming units with average insert size of 1.4 kb, ranging from 0.5 kb to 4.2 kb and was quantified to construct a cDNA library. Eight hundred and fourteen ESTs were compared with sequences in GenBank database of NCBI using Blast search, among which 65 ESTs and cDNA clones had been identified. These identified ESTs were GR410172–GR410229. The cDNA library provides rich source for better understanding of functional genes in sea urchin, and thus will play an important role in further development of sea urchin research.