Objective To explore the effect of honokiol on serum inflammatory factors, extracellular matrix component expression, and apoptotic pathway-related protein expression in rats with D-galactose-induced intervertebral disc degeneration. Methods Forty-five SD rats were randomly divided into control ( Control), D-galactose ( D-gal) model (Model), honokiol low dose (2 mg / kg), honokiol medium dose (4 mg / kg) and honokiol high dose (8 mg / kg) groups, with 9 rats in each group. The rat model of intervertebral disc degeneration was established by subcutaneous injection of D- galactose in model and honokiol groups, and the Control group was subjected to subcutaneous injection of normal saline. After successful modeling, administration group rats were gavaged with magnolol at 2, 4 and 8 mg / kg, and the remaining rats were gavaged with normal saline in each group. Rats were sacrificed after 4 weeks of continuous administration. HE and safranin O staining was used to observe and compare the morphology and histology of intervertebral discs in each group. The mRNA levels of extracellular matrix components were measured by qRT-PCR in rat intervertebral discs. Changes of interleukin IL-1β, IL-6, tumor necrosis factor-α ( TNF-α) and IL-10 in rat serum were detected by ELISAs. TUNEL staining was performed to observe apoptosis of rat intervertebral disc. Protein expression of B-cell lymphoma protein 2(Bcl- 2) / Bcl-2 associated X protein ( Bax), Caspase-9, Caspase-3 and c-Myc was detected by Western blot. Results The scores of intervertebral disc histomorphology in the D-galactose group and honokiol low and medium dose groups were significantly higher than that in the control group (P<0.05). Compared with that in the D-galactose group, the scores of intervertebral disc histomorphology in medium and high dose honokiol groups were significantly lower (P<0.05). Cartilage damage in the model group and the honokiol low dose group was severe, and that in honokiol medium and high dose groups was slightly damaged. Honokiol significantly increased the expression levels of SRY-related high mobility group-box gene 9 ( SOX-9), collagen II and aggrecan (P<0.05). The levels of IL-1β, IL-6, TNF-α and IL-10 in the D-galactose group and honokiol medium and high dose groups were significantly higher than those in the control group (P<0.05). Compared with that in the D-galactose group, the levels of IL-1β, IL-6 and TNF-α in the honokiol medium and high dose groups were reduced significantly (P<0.05), and the content of IL-10 was increased significantly (P<0. 05). Compared with that in the control group, the number of apoptotic cells in the model group and honokiol low and medium dose groups was increased significantly (P< 0. 05), the Bcl-2/ Bax ratio decreased significantly (P< 0.05), and the protein levels of Caspase-9, Caspase-3 and c-Myc were increased significantly ( P< 0.05). Compared with that in the model group, the number of apoptotic cells in the honokiol medium and high dose groups was decreased significantly (P<0. 05), the Bcl-2/ Bax ratio was increased significantly (P<0.05), and the protein levels of Caspase-9, Caspase-3 and c-Myc were decreased significantly (P<0.05). Conclusions Honokiol has obvious therapeutic effects on lumbar intervertebral disc degeneration induced by D-galactose.