Bone morphogenetic proteins (BMPs) play important roles in a lot of biological processes, such as bone development, cell proliferation, cell differentiation, growth, etc. However, the functions of abalone BMP genes are still unknown. This study aimed to better understand the characterization and biological function of BMP7 ofHaliotis discus hannai(hdh-BMP7) via cloning and sequencing analysis. The coding sequence (CDS) length of hdh-BMP7 is 1251 bp, which encodes 416 amino acids including a signal peptide (1–28 aa), a transforming growth factor-β (TGF-β) propeptide (38–272 aa), and a mature TGF-β peptide (314–416 aa). The analysis of expression showed thathdh-BMP7 mRNA was widely expressed in all the examined tissues ofH. discus hannai. Four SNPs were related to growth traits. The results of RNA interference (RNAi) showed that the mRNA expression levels ofhdh-BMPRI,hdh-BMPRII,hdh-smad1, andhdh-MHCdeclined afterhdh-BMP7 was silenced. After RNAi experiment for 30 days, the shell length, shell width, and total weight were found to be reduced inH. discus hannai(p< 0.05). The results of real-time quantitative reverse transcription PCR revealed that thehdh-BMP7 mRNA was lower in abalone of the S-DD-group than in the L-DD-group. Based on these data, we hypothesized that BMP7 gene has a positive role in the growth ofH. discus hannai.