Abstract: Objective To expore the relationship between gestational weight gain and neonatal birth outcomes.Methods A total of 793 pregnancy women who gave birth in Shenzhen Guangming New District People's Hospital between Jan. 2016 and May 2017 and their infants were selected as the subjects. The data of gestational weight gain and neonatal birth outcomes (including birth weight, gestational age and delivery complications) was collected. This study was conducted to find out gestational weight gain according to Institute of Medicine 2009 recommendation and the relationship between the gestational weight gain of the women and newborn birth outcome.Results Gestational weight gain of 793 pregnant women ranged from 5 to 34 kg (mean 14.01 ± 4.32) kg. There were 227 (28.6%) pregnant women with less weight gain, 321 (40.5%) with adequate weight gain and 245 (30.9%) with more weight gain according to recommendation. The gestational age and birth weight of infants of pregnant women with less weight gain was shorter and lower than the other groups. Incidence of preterm in less weight gain grouwas also higher than the other groups. Less weight gain during pregnancy was associated with preterm (OR:2.93, 95% CI:1.16-6.26) and neonatal asphyxia (OR:3.86, 95% CI:1.36-10.98).More weight gain during pregnancy was associated with macrosomia (OR:4.51, 95% CI:1.23-16.57).Conclusions The prevalence of less and more weight gain during pregnancy was relative high in Shenzhen district. Abnormal gestational weight gain was associated with adverse neonatal birth outcome.