Abstract: Objectives To analysis the main characteristics and changes of the internal death in pediatric intensive care unit (PICU) in the past five years. Methods The clinical data of 330 death cases in PICU internal medicine were retrospectively analyzed from January 2008 to December 2012. Results The mortality rate in PICU dropped from 5.85% to 3.96% from 2008 to 2012. Among 330 death cases, 136 cases (41.2%) were infants, 73 cases (22.1%) were toddlers, 51 cases (15.45%) were preschoolers, and 70 cases (21.21%) were school-age and adolescence. In different years, the differences of distribution of death in different age groups were statistical significance (χ2=6.90, P=0.009). In all years, the infant had the highest death rate. As the time progresses, the death rate of the infant and young children decreases, while the death rate of the school-age and adolescence increases. Among the diseases caused death, the cardiovascular disease was the most common disease (33.94%), followed by hematologic malignancy (31.52%). The difference of distribution of the diseases caused death in different age group was statistically significant (P<0.01). The cardiovascular disease was main cause of death in infant, and the hematologic malignancy was the main cause of death in other three age groups. Within 24 h admission, the pediatric critical illness score (PCIS) had been assessed, 67.49% was critical and 15.48% was extremely critical. The hospitalization time was negatively correlated with PCIS (r=－0.313, P<0.001). Conclusions In the past five years, the mortality in PICU declined year by year. Cardiovascular disease in infancy and hematologic malignancy in non infancy are the leading cause of death in children. Admission in critical or extremely critical condition is the reason of early death in hospital.