The brain grows and develops rapidly during childhood. To support this growth, blood and nutrients must be delivered and distributed throughout the brain. Adequate cerebral blood flow (CBF) is essential for proper brain function and development. Previous studies have shown CBF increases during infancy and decreases during adolescence, yet we did not know when the increases changed to decreases because no one had thoroughly studied CBF changes during early childhood. This study aimed to identify developmental changes of CBF and evaluate sex differences in young children 2-7 years. Arterial spin labeling, a magnetic resonance imaging (MRI) technique, was used to map age-related changes of CBF in a large longitudinal sample of 96 participants ages 2-7 years. Steady increases of CBF were found across early childhood in many different brain regions. Boys and girls showed similar age-related changes. Our results show that CBF continues to increase until at least 7 years. These changes happen alongside improvements in brain structure and function, suggesting that CBF provides ongoing support for growth, learning, and behaviour.