The current study aims to compare the differences in the CD64 index [the granulocyte:lymphocyte ratio of CD64 expression via mean fluorescence intensity (MFI)] and conventional clinical indicators (WBC, PCT and CRP) among the control, non-sepsis and sepsis groups by analyzing the receiver-operating characteristic curves (ROC), thus determining their value in clinical practice in the early diagnosis of neonatal infection. The gene discussed is CRP; the disease is Sepsis.