Objective: The aim of this study was to understand different clinical characteristics of early preterm infants (EPIs) and late preterm infants (LPIs). Materials and Methods: The clinical and laboratory data of 561 preterm infants, admitted to this hospital from January 2013 to December 2014, were comparatively analyzed. Results: EPIs accounted for 27.45% and LPIs accounted for 72.55%. The incidence rates of asphyxia at birth, placental abruption, and placenta previa in EPIs were significantly higher than those in LPIs (p < 0.01). The levels of albumin, globulin, triglycerides, serum phosphorus, serum iron, and hemoglobin in EPIs were significantly lower than those in LPIs (p < 0.01). The proportion of low body temperature, low blood sugar, respiratory distress, apnea and feeding intolerance, as well as assisted ventilation therapy, in EPIs were significantly higher than those in LPIs (p < 0.01). Conclusions: LPIs accounted for the majority of preterm infants, placental abruption and placenta previa were the unique risk factors in EPIs, EPIs had lower nutritional reserves than LPIs, and would be more susceptible to the perinatal complications.