OBJECTIVE: To explore diseases in the neonatal period among hospitalized preterm infants. METHODS: The clinical data of 961 preterm infants who were hospitalized in three hospitals in Changsha in 2008 were retrospectively reviewed. RESULTS: The most common neonatal disease was respiratory system diseases (73.8%), followed by infectious diseases (39.4%) and nervous system diseases (38.3%). With the increase of gestational age and birth weight, the incidence of circulatory system diseases showed no statistically significant differences (all P＞0.05), while the incidences of other diseases, such as respiratory system diseases, neonatal infections, nervous system diseases, and the desirable outcome of the preterm infants became significantly different (all P<0.05). Increased birth weight and gestational age were the protective factors while neonatal asphyxia, hyperbilirubinemia and neonatal scleredema were the risk factors for the outcome of preterm infants. CONCLUSIONS: The common neonatal diseases for preterm infants are respiratory system diseases, neonatal infections, and nervous system diseases. The incidence of the common diseases is reduced with the increasing gestational age and birth weight. Interventions should be carefully planned based on the protective factors (increased birth weight and gestational age) and risk factors (neonatal asphyxia, hyperbilirubinemia and scleredema) of the outcomes of these diseases.