Purpose: It is often assumed that phonological awareness only reflects children's phonological skill. However, orthographic representations have been found to be automatically involved during phonological awareness tasks, which we refer to as automatic orthographic activation. Although previous longitudinal neural studies have addressed how phonological processing during phonological awareness tasks is bidirectionally related to reading skill in developing children, we do not know how automatic orthographic activation plays a role in reading skill. Method: To address this gap, we measured 40 children's reading skill and brain activity during an auditory phonological task at two time points using functional magnetic resonance imaging. Children were 5.5 to 6.5 years old at the first time point and were followed up approximately 1.5 years later when they were 7 to 8 years old. Results: We found that earlier reading skill predicted children's later functional connectivity during onset processing between the left superior temporal gyrus, a phonological region, and the left posterior ventral occipitotemporal cortex, an orthographic region representing letters. Conclusion: This finding, together with previous studies, suggests that learning to read influences phonological awareness not only by refining phonological representations but also via strengthening the automatic mapping between phonemes and letters during spoken language processing.