Understanding the nature of dynamic neural interactions during development is a critical issue of cognitive neuroscience. However, our knowledge on infants’ functional connectivity (FC) dynamics is still scarce. Leveraging longitudinal infant resting-state fMRI from fifty-one typically developing infants, we, for the first time, charted the development of dynamic functional networks in the first two postnatal years. The results show that many high-order cognitive function-related brain regions have significantly increased temporal variability in the FC patterns, suggesting that the brain network is gradually reconfigured towards a more flexible, dynamic, and adaptive system, which mirrors the rapidly developing complex functions in early infancy.