【Abstract】 Objective To investigated the neuroprotective e££ectes of d 1-3-n-Butylphthalide on the damage of dopaminergic neurons induced by age-associated activated microglia. Methods The primary culture of rat microglia and the subculture of PCI 2 cell line were used. Phorbol ester induced the abnormal activation o£ microglia. Different doses of NBP pretreated PCI 2 cells, and then low doses o£ rotenone were added to establish a co culture system with aging microglia 9 simulating the extracellular cell model o£ Parkinson's disease. The morphology o£ PCI 2 cells was observed under the inverted microscope, and flow cytometry was used. The mitochondrial membrane potential and intracellular reactive oxygen species o£ PCI 2 were detected, and the apoptosis o£ PCI 2 was detected by annexin V PI double staining. Results Compared with the normal group, the mitochondrial membrane potential of PCI2 cells co cultured with aged microglia decreased and ROS production increased (P＜ 0. 01) , while NBP o£ 0. 01~100 μm could inhibit this change in varying degrees. Conclusion NBP can reduce apoptosis of PCI 2 cells and protect neurons by inhibiting mitochondrial permeability and reducing oxidative stress.