[Objective] To explore the effect of andrographolide (Andro) on the biological behavior of rat nucleus pulposus cells (NPCs) in vitro and its mechanism. [Methods] NPCs were treated with tert-buttyl hydroerioxide (TBHP) to construct apoptosis model. The normal NPCs and TBHP-induced NPCs were treated with different concentrations of Andro, CCK8 assay for toxicity was conducted to select the op- timal concentration and time of Andro action. The cells were divided into blank control (BC) group, TBHP (T) group, TBHP+Andro (TA) group, TBHP+Andro+PI3K inhibitor (LY294002) (TA-Pih) group and TBHP+PI3K inhibitor (T-Pih) group, and were given corresponding treatment in vitro. The cell apoptosis was detected by flow cytometry, the levels of inflammatory cytokines were detected by ELISA, and the protein expression levels of apoptotic markers were detected by Western blot. [Results] The optimum concentration and reaction time of An- dro were 18μmol/L and 24 h respectively. Compared with the BC group, the apoptosis rate, TNF-α, IL-1β, IL-6 levels and Bax protein lev- el in the T group were significantly increased (P＜0.05) , while the protein levels of Bcl-2 and p-Akt were significantly decreased (P＜0.05) . Compared with the T group, the apoptosis rate, TNF-α, IL-1β, IL-6 levels and Bax protein level in the TA group were significantly de- creased (P＜0.05) , while the protein levels of Bcl-2 and p-Akt were significantly increased (P＜0.05) , while which as a trend was opposite in the T-Pih group. Compared with the T-Pih group, the apoptosis rate, TNF-α, IL-1β, IL-6 levels and Bax protein level in the TA-Pih group were significantly decreased (P＜0.05) , while the protein levels of Bcl-2 and p-Akt were significantly increased (P＜0.05) . [Conclusion] Andro does inhibit cell apoptosis and reduce the level of inflammatory cytokines, which may be related to the regulation of PI3K/Akt pathway.