Oxidative stress is one of the main causes of neurodegenerative diseases such as Alzheimer's disease (AD). Our previous studies have shown that artemisinin, a anti-malaria Chinese medicine, with neuroprotective effect, however, the antioxidative effect of artemisinin and its potential mechanism remain to be elucidated. In the present study, the protective effect and the underlying mechanism of artemisinin against injury of hydrogen peroxide (H2O2) in SH-SY5Y and hippocampal neurons were studied. Our results show that artemisinin protected SH-SY5Y and hippocampal neuronal cells from H2O2-induced cell death at clinically relevant concentrations in a concentration-dependent manner. Further studies showed that artemisinin significantly reduced cell death caused by H2O2 by restoring nuclear morphology, abnormal changes in intracellular ROS, activation of caspase-3, lactate dehydrogenase release and mitochondrial membrane potential. Hoechst staining and flow cytometry showed that artemisinin significantly reduced the apoptosis of SH-SY5Y cells exposed to H2O2. Western blot analysis showed that artemisinin stimulated the phosphorylation and activation of AMP-activated protein kinase (AMPK) in SH-SY5Y cells in a time and concentration-dependent manner, whereas the application of AMPK inhibitor Compound C or decrease in expression of AMPKα with shRNA specific for AMPKα blocked the protective effect of artemisinin. Similar results were obtained in primary cultured hippocampal neurons. Taken together, these results indicate that artemisinin can protect neuronal cells from oxidative damage, at least in part through the activation of AMPK. Because artemisinin is relatively inexpensive and has few side effects, our findings support the role of artemisinin as a potential therapeutic agent for neurodegenerative diseases.