Abstract: Objective By the use of GM(1,1) model to predict mortality trends of children under 5 years, on the basis of the analysis of cause of death in children under 5 from 2006 to 2012 in Zhabei District of Shanghai City.Methods Nearly 5 years of monitoring data were used for analysis of the cause of death, and the grey model (GM) was used to fit and predict mortality.Results The death of children under 5 was mainly infant death and the infant death was mainly newborns death from 2006 to 2012 in Zhabei District. During this five-year period, children mortality under 5 fluctuated from 3.30‰ to 4.98‰ and was slightly increased in 2010. The main cause of death in the neonatal period was birth asphyxia,accounting for 31.82%. For infant period,The first cause was congenital anomaly,accounting for 30.43% and the second cause was birth asphyxia,accounting for 20.29%. The fitting effect of GM was fine and the predicted mortality of children under 5 years was 3.88‰ in 2013.Conclusion Congenital anomalies, birth asphyxia and accident death seriously threaten the lives of children under 5 years. We must strengthen neonatal screening, neonatal accidental death education, thus effectively reducing the mortality of children under 5.The fitting effect of GM(1,1) on mortality rate of children under 5 is good and can be applied for prediction.