Baicalin, a type of flavonoid extracted from the dried root of Scutel aria baicalensis georgi, has been shown to effectively inhibit cellapoptosis. Therefore, we assumed that baicalin would suppress colistin sulfate-induced neuronal apoptosis. PC12 cells exposed to colistin sulfate (62.5-500 μg/mL) for 24 hours resulted in PC12 cellapoptosis. In addition, caspase-3 activity, lactate dehydrogenase level and free radical content increased in a dose-dependent manner. Subsequently, PC12 cells were pretreated with baicalin (25, 50 and 100 μg/mL), and exposed to 125 μg/mL colistin sulfate. cellmorphology markedly changed, and cellviability increased. Moreover, caspase-3 activity, lac-tate dehydrogenase level and free radical content decreased. Results indicated that baicalin inhib-ited colistin sulfate-induced PC12 cellapoptosis by suppressing free radical injury, and reducing caspase-3 activity and lactate dehydrogenase activity.