<p>Previous studies have identified the left fusiform gyrus and the left inferior frontal gyrus as orthographic systems shared between reading and writing in adults. Since children’s reading and writing abilities are still developing, it remains unclear whether they share a lexical orthographic system for reading and writing. In this study, functional near-infrared spectroscopy was employed to investigate whether reading and writing share a lexical orthographic system in children. The reading task required participants to identify visually presented Chinese characters. The writing task required participants to retrieve the orthography of the target character in a two-character word presented auditorily. The findings revealed that the left fusiform gyrus and the triangularis pars of bilateral inferior frontal gyrus were activated in both the reading and dictation tasks, which may constitute a shared orthographic system for reading and writing. However, differences in the stability of activation intensity across tasks were observed. The activation intensity in the triangularis part of bilateral inferior frontal gyrus exhibited cross-task stability, but that of the left fusiform gyrus was modulated by the input modality. The orthographic system shared between reading and writing in children is not entirely identical to that in adults. Children recruit more brain regions for orthographic processing, as evidenced by significant activation in the right inferior frontal gyrus. Children have less extensive reading and writing experience than adults do and therefore require more cognitive resources for reading and writing processing.</p>