Introduction: C-Reactive Protein (CRP) is most common of the inflammatory marker to determine whether a newborn has bacterial infection in the neonatal intensive care unit (NICU). However, CRP could elevate in a variety of situation other than bacterial infection. The aim of this study is to identify clinical conditions increasing Procalcitonin (PCT) in infant with elevated CRP at early of life. Methods: The study included late preterm or full-term infants with elevated CRP(＞6mg/L) and tested PCT on 3rd day (48-72hr) of life who admitted to NICU of Jeonbuk National University Hospital from Jan. 2019 to Jul. 2021. Blood tests with hemolysis were excluded. The abnormal PCT is defined as higher than 2.5ng/mL of PCT on 3rd day (48-72hr). Result: We analyzed risk factors for the abnormal PCT in late preterm or term infant with elevated CRP. The gestational age and birth weight of 104 enrolled were 37.9±1.4weeks and 3070.3±638.0g. Forty-one (39.4%) had abnormal PCT. Invasive ventilator were more used, the incidence of early sepsis and respiratory distress syndrome were higher in neonate with abnormal PCT (P＜0.05). There was not any other differences in blood tests or clinical characteristics. Multivariate analysis revealed that RDS (adjusted odd ratio 12.62; 95% confidence Interval 2.65-60.11; P＜0.05) and early sepsis (10.42; 3.53-12.09) independently increased the risk of abnormal PCT on 3rd day of birth. Conclusion: RDS, besides early sepsis, should be considered if late preterm or full-term infants at early life with increased CRP are also elevated PCT.