Objective:To analyze the clinical characteristics, etiology and outcome of early-onset neonatal sepsis (EONS) and late-onset neonatal sepsis (LONS).Methods:The clinical data of 265 neonates with NS admitted in the neonatal ward of the the Affiliated Hospital of Qingdao University from January 2014 to September 2020 were enrolled, including 76 cases of EONS and 189 cases of LONS. The general information, clinical manifestation, laboratory findings, pathogen distribution, treatment and outcome of the two groups were analyzed with SPSS25.0 statistical software.Results:The rates of meconium-stained amniotic fluid, prenatal maternal fever, abnormal white blood cell (WBC) count and neutrophil count in EONS group were significantly higher than those in LONS group ( P<0.05 or <0.01). However, the rates of indwelling central venous catheters, mechanical ventilation, fever, abdominal distension, abnormal platelet count and serum prealbumin level in LONS group were significantly higher than those in EONS group ( P<0.05 or <0.01). Staphylococcus epidermidis(135/265)and Staphylococcus aureus (22/265) were the most common gram-positive bacteria and Escherichia coli (13/265) was the most common gram-negative bacteria in NS. The proportion of gram-positive bacteria was the highest in both EONS group (85.5%) and LONS group (84.7%), which was mainly Staphylococcus epidermidis of coagulase negative staphylococci. The proportion of Listeria monocytogenes and Streptococcus infections in EONS group was significantly higher than that in LONS group ( P<0.05 or <0.01). The proportion of Staphylococcus aureus infection in LONS group was significantly higher than that in EONS group ( P<0.01). There was no significant difference in case fatality rate between EONS group and LONS group (6.6% vs 2.6%, P>0.05). Conclusions:Perinatal amniotic fluid pollution and prenatal maternal fever are risk factors for the occurrence of EONS, while indwelling central venous catheter and mechanical ventilation are risk factors for the occurrence of LONS. Abnormal platelet count and abnormal serum prealbumin are more common in the LONS group. The bacteria detected in EONS and LONS are mainly Staphylococcus epidermidis. Clinical diagnosis and treatment of EONS and LONS should be managed differently.