Objectives: 1. Describe neonatal classification of WHO. 2. Identify some principal clinical and paraclinical signs of term, preterm, post term babies. Patients and method: an observational descriptive study of 233 newborns hospitalized in neonatal unit at Hue university‘ s hospital was done during 12 months from 01/01/2009 to 31/12/2009 for describing neonatal classification and identifying principal clinical and paraclinical signs. Results: Premature (16.74%); Term babies (45.5%); Post term (37.76%); Premature: asphyxia (43.59%), hypothermia (25.64%), vomit (30.77%), jaundice (61.54%), congenital malformation (17.95%); CRP > 10mg/l (53.85%); anemia Hb < 15g/dl (12.82%). Term babies: poor feeding (21.7%); fever (24.53%); CRP > 10mg/l (53.77%); Hyperleucocytes/ Leucopenia (35.85%). Post term: respiratory distress (34%); lethargy (29.55%); vomit (26.14%); polycuthemia (1.14%); hypoglycemia (22.73%). Conclusion: each of neonatal type classified by WHO presente different clinical and paraclinical. Signs. The purpose of this research is to help to treat neonatal pathology more effectively.