Abstract: Objective To review the evidence regarding neuroprotective effects of antenatal exposure to magnesium sulfate. Methods We conducted database searches of PubMed, Cochrane library, EMBASE, China Journal Full-text Database, Chinese Biomedical Database, Chinese Scientific Journals Full-text Database. Randomized controlled trials comparing Magnesium Sulfate with placebo/other treatment in patients at risk of preterm labor were evaluated for inclusion and methodological quality. The data was analyzed by RevMan 5.0. The outcomes were death with cerebral palsy by 18~24 months corrected age, death, cerebral palsy, moderate-severe cerebral palsy, and death with moderate-severe cerebral palsy. Result Five randomized controlled trials were included （5 235 fetuses/ infants）. When analyzed by GA（gestational age） at randomization, in utero exposure to magnesium sulfate during 30~34 weeks did not reduce the rate of death or cerebral palsy （RR 0.93, 95%CI 0.79~1.09）. However, cerebral palsy （RR 0.70, 95%CI 0.54~0.90）, moderate-severe cerebral palsy（RR 0.61, 95%CI 0.44~0.84）, and death with moderate-severe cerebral palsy were significantly reduced, without an evident increase in risk death（RR 0.99, 95%CI 0.82~1.19）. Similar results were obtained when the GA at randomization was less than 30 weeks. When only neuroprotection trials （four trials, 4 324 fetuses/infants） are analyzed, in utero exposure to Magnesium Sulfate additionally reduced the outcome of cerebral palsy. Conclusion Fetal exposure to Magnesium Sulfate in women at risk of preterm delivery significantly reduces the risk of cerebral palsy without increasing the risk of death.