Here, we investigated the effects of different concentrations of transforming growth factor β1 (TGF-β1) on the regulation of aggrecan (ACAN), collagen type II (COL2A1), and SRY-box 9 (Sox9) gene expression in human nucleus pulposus cells in vitro. Second-generation human nucleus pulposus cells were grown in culture media containing 4 different concentrations of TGF-β1 (0.1, 1.0, 10, and 100 μg/L). The control group was not treated with TGF-β1. Then, reverse transcription polymerase chain reaction was used to measure the gene expression of ACAN, COL2A1, and Sox9. There were no significant differences in expression between the control group and the group treated with 0.1 μg/L TGF-β1. However, significant increases in the expression of ACAN, COL2A1, and Sox9 were observed as the concentration of TGF-β1 increased, and expression was highest following treatment with 10 μg/L TGF-β1. Thus, TGF-β1 induced the expression of ACAN, COL2A1, and Sox9 in nucleus pulposus cells, suggesting that TGF-β1 may play an important role in the prevention and treatment of intervertebral disc degeneration.