To study the neuroprotective effect of inulin-type oligosaccharides extracted from yacon （YOs）， the antioxidant activity in vitro and cytoprotective effect were applied. The antioxidant activity of YOs was evaluated by the DPPH radical scavenging capacity， ABTS radical scavenging capacity and the ferric reducing antioxidant power （FRAP） assays. The cytoprotective effect was evaluated by H2O2-induced SH-SY5Y injured cells model. The results of antioxidant activity showed the IC50 of DPPH and ABTS were（0.272±0.078） mg/mL， equivalent to（141.01 ± 15.67） Trolox μmol/g YOs， 2.67 ± 0.89 mg/mL， equivalent to（195.81±8.13） Trolox μmol/g YOs， respectively， and the FRAP value was （10.12±0.35） mmol/g， equivalent to （82.40±1.59） Trolox μmol/g YOs. In addition， YOs （0.5 and 1 mg/mL） significantly restored the injury on SH-SY5Y induced by H2O2 （200 μmol/L）. In conclusion， YOs possess good antioxidant activities and significant cytoprotective effect against oxidative stress injury on SH-SY5Y cells， which suggests it’s prospective in preventing or forestalling brain aging.