['Reference ranges for vital signs may differ significantly among children of different ethnic origins.', '(1) To validate the Advanced Paediatric Life Support (APLS) age-based vital signs reference ranges in Chinese children in Hong Kong. (2) To derive age-based centile curves for systolic blood pressure, heart rate and respiratory rate for Chinese children. (3) To summarize the reference ranges in a table format appropriate for applying APLS to ethnic Chinese patients.', 'A cross-sectional study was performed on a population of healthy Chinese children recruited from 8 kindergartens and 6 primary schools in Hong Kong. Trained operators visit the sites to obtain measurements. Age-groups: small toddlers (12-23 months); pre-school (24-59 months); and school (60-143 months). Z-test was used to assess statistical significance for proportions of each parameter falling outside the APLS reference range. One-sample t-test was used for comparison with APLS means according to age-groups. LMS Chartmaker Pro v2.3 software was used to describe the data in centile curves.', "A total of 1353 patients (55.1% boys) were included. For heart rate, systolic blood pressure and respiratory rate respectively, 34.1%, 55.9% and 55.7% of corresponding measurements were outside the APLS age-based reference ranges. In the 'pre-school' and 'school' age-groups, the mean value for blood pressure is significantly higher, and the mean values for heart rate and respiratory rate significantly lower, in comparison to APLS mean values."] Do validation of the APLS age-based vital signs reference ranges in a Chinese population?