Our previous study demonstrates that SYB produces a neuroprotective effect in vivo. In the present study, we investigated the protective effect of safflor yellow B (SYB) on the acute oxidative injury induced by H(2)O(2) and mechanisms in PC12 cells. H(2)O(2) was used to mimic in vitro model of the oxidative injury and to induce apoptosis in PC12 cells. The cells were pretreated with the different concentrations of SYB. The cell viability, lactate dehydrogenase (LDH) release, malondialdehyde (MDA), and superoxide anion levels, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were measured. Caspase 3 activity, Bcl-2 and Bax expressions were also observed. The results showed that exposure of the cells to H(2)O(2) significantly decreased the cell viability, SOD and GSH-Px activities and Bcl-2 expression, and increased LDH release, superoxide anion and MDA generations, caspase 3 activity and Bax expressions. Pretreatment of the cells with SYB was able to remarkably antagonize the H(2)O(2)-induced changes in dose-dependent way. These suggest that SYB is able to protect PC12 cells from H(2)O(2)-induced injury and apoptosis via antioxidant and anti-apoptotic mechanisms.