To analyze the clinical data of very low birth weight infants (VLBWIs) and extremely low birth weight infants (ELBWIs) (birth weight ≤1 200 g) and to provide prewarning indicators for prognostic evaluation and clinical intervention.A retrospective analysis was performed on the clinical data of 108 VLBWIs and ELBWIs to investigate the maternal history of diseases during pregnancy, neonatal birth status, the process of diagnosis and treatment, and prognosis. Unconditional logistic regression analysis was used to determine prognostic factors.Of the 108 preterm infants, 15 had a birth weight of <800 g, 29 had a birth weight of 800-999 g, and 64 had a birth weight of 1000-1200 g. The mortality was 33.3% (36/108). Placenta previa and Apgar score ≤3 at 5 minutes were the main risk factors for death within 24 hours of birth; premature rupture of membrane, Apgar score ≤3 at 5 minutes, and pulmonary hemorrhage were the main risk factors for death between 24 hours and 7 days after birth; late-onset sepsis caused by invasive fungal infection was an independent risk factor for death over 7 days after birth, while pregnancy-induced hypertension syndrome was a protective factor.The mortality in VLBWIs and ELBWIs is relatively high, and the prognostic factors vary between preterm infants of different ages. Clinicians should discuss management options for the infants on the basis of these findings to increase the survival of preterm infants.