Human neuroblastoma SH-SY5Y was induced to differentiate into mature neuronal cells,and the cell model of Tau hyperphosphorylation was further established by okadaic acid (OA) to investigate the protective effect of quercetin and quercetin-3-O-β-D-glucuronide.The cell viability was measured by MTT.Morphological changes of SH-SY5Y cells were observed by Giemsa staining.The degree of phosphorylation of Tau protein (Ser396,Ser262) was detected by Western blot.Intracellular reactive oxygen species (ROS) levels in cells were measured by flow cytometry.The variations of ATP content in cells were detected by chemiluminescence.The results showed quercetin and quercetin-3-O-β-D-glucuronide decreased intracellular ROS production and increased ATP content,leading to attenuate Tau hyperphosphorylation.In addition,the neuroprotective effect of quercetin exhibited stronger than that of quercetin-3-O-β-D-glucuronide.