Beta-2 adrenergic receptor is a G protein coupled receptor, which is closely related to biological activities such as growth, endocrine and metabolism. The sequence of beta-2 adrenergic receptor was screened from the transcriptional library of the razor clam Sinonovacula constricta, and the full-length sequence of beta-2 adrenergic receptor was obtained by PCR and RACE technology, named as ScADRB2. The cDNA length of ScADRB2 was 1 497 bp, including 148 bp 5' untranslated region, 191 bp 3' untranslated region, and 1 158 bp open reading frame, encoding 385 amino acids. Primers were designed in ORF to detect the expression level in hemolymph,liver, waterpipe, foot, mantle, gill, and gonad, by quantitative real-time PCR, respectively. The results showed that the expression of ScADRB2 was the highest in the mantle, relatively high in the foot, lower in the siphon and gonad, but the lowest in the hemolymph, liver and gills. Tissue injury experiment was designed and the samples were collected at 8 h, 24 h, 48 h, 60 h and 72 h after injuring siphon. The results showed that the expression level of ScADRB2 was higher at 8 h and 24 h, decreased significantly at 36 h, increased at 48 h, and decreased at 60 h or 72 h. The results showed that beta-2 adrenergic receptor might be involved in the process of damage and repair of S. constricta.