There is increasing evidence that cardiorespiratory endurance (CRE) is declining among Chinese children and youth. The 20-meter shuttle run test (20-m SRT) is considered the most effective and widely used field-based measurement of CRE for children and youth worldwide. However, there have been few attempts to set 20-m SRT norms for Chinese children and youth. We aimed to develop sex- and age-specific 20-m SRT norms for Chinese children and youth, and compare them with international standards. Participants were 69,960 healthy children and youth aged 9-17 years from six geographical areas of China, selected using a stratified cluster random sampling method. Sex- and age-specific 20-m SRT percentiles and curves were extracted for four common 20-m SRT metrics (laps, completed stages/minutes, speed at the last complete stage, estimated peak oxygen uptake). We also estimated the prevalence of healthy CRE according to the interim international cut-points (42 mL.kg^-1min^-1 for boys, 35 mL·kg·¹min^-1 for girls). Chinese boys consistently outperformed girls, while more girls (86.4%) exhibited healthy CRE than boys (67.1%). Younger children and youth were more likely to meet the standards compared with the older, regardless of sex. Chinese children and youth underperformed international norms by 0.85% for boys and 3.1% for girls. The performance indicator (z-score) of Chinese children and youth was -0.01, indicating that 20-m SRT performance was worse than the international mean. The sex differences were also higher for international than Chinese students. This study provided national sex- and age-specific 20-m SRT Chinese norms, offering a valuable tool for screening, monitoring and identifying target groups for future interventions and early prevention of cardiovascular risk factors.

• Provided national sex- and age-specific 20-m SRT Chinese norms, offering a valuable tool for screening, monitoring and identify target groups for future interventions and early prevention of cardiovascular risk factors.

• Estimated the prevalence of healthy CRE and performed comparisons with international standards.