This study aimed to determine the cardiovascular responses of children to maximal treadmill exercise with Bruce Treadmill Protocol and to compare these responses between girls and boys. A total number of 20 subjects with age ranging from 5-11 years were included in the study. Subjects were separated to two groups i.e. group A, group B on the basis of their gender. Group A comprised of 10 girls, while 10 boys made up Group B. The treadmill is started at Stage-1 which has a speed of 2.7 km/hr and an incline of 10%, after 3 minutes both speed and incline is increased to 4.0 km/hr and 12% respectively to Stage 2. Blood pressure was recorded in supine position immediately after completion of exercise and at 1,2,3,4,5,6,7,8,9 and 10 minutes of recovery.Heart rates was recorded at each minute of the recovery, till it became stable.Recorded data show that there is no significant, difference in both the vascular variables of Heart rate and Blood pressure in response TST both during Exercise and during Recovery Levels of circulating hormones especially around the period of puberty, help to explain some of the sex differences in anaerobic fitness but the evidence is equivocal and current data suggest that sexual maturity does not exert any independent effect on anaerobic fitness once age, body mass, body composition are concurrently controlled for., Improvements in neural adaptations with age, complete myelination of nerve fibres, improved muscle coordination during multi-joint exercise and an improved capability to recruit motor units or more fully activate muscles help to explain age-related improvements in anaerobic fitness.