The purpose of the present study was to examine the relationship between oxygen uptake (VO[subscript 2]) and heart rate (HR) responses during rest and exercise in Chinese children and youth and to evaluate the relationships between maximal heart rate (%HRmax), heart rate reserve (%HRR), peak oxygen uptake (%VO[subscript 2]peak), and oxygen uptake reserve (%VOsubscript 2]R) in Chinese children and youth. Forty-nine Chinese children and youth were studied at rest and during a graded maximal exercise test on treadmill. Resting, submaximal and peak HR and VO[subscript 2] were collected. Regression analyses were conducted to investigate the associations between the various forms of HR and VO[subscript 2] measures. The equivalency between %HRR and %VO[subscript 2]R for adults was examined for children using data obtained in this study. Results indicated that all regression lines between HR measures and VO[subscript 2] measures were significantly different from the line of identity (p less than 0.05), except the regression line for %HRR versus %VO[subscript 2]peak in boys. The equivalency between %VO[subscript 2]R and %HRR for adults was not demonstrated in children and adolescents in this study. In contrast, %HRR was more closely equivalent to %VO[subscript 2]peak. Because a strong linear relationship was found between HR and VO[subscript 2], HR measures, in terms of either %HRmax or %HRR, would still be a practical variable for prescribing appropriate exercise intensity for children and adolescents. Unlike results found for adults, a given %HRR in children and youth was not equivalent to its corresponding %VO[subscript 2]R. (Contains 6 tables and 3 figures.)