Objective:To research Sonic Hedgehog (Shh) signaling pathway effects on the cerebellum external granular layer (EGL layer) cell granule cell precursors (GCP cell) proliferation and migration in early development of cerebellum. Methods: Paraffin sections by immunofluorescence were performed to observe external granular layer of the cerebellum GCP cell proliferation. Mouse brain slices in vitro establish systems were performed to detect dynamic migration and proliferation of cerebellar external granular layer of GCP cells. Results: The number of granulosa cell proliferation precursors was reached the peak on the seventh days after birth in mice cerebellar external granular layer;Shh signaling pathway promoted proliferation of cerebellar external granular layer cells. After inhibition of the signaling pathway by cyclopamine (CPA), cell proliferation of cerebellar external granular layer was inhibited, but migration was unaffected. Conclusion: Shh signaling pathway is a part of promoting cell proliferation of cerebellar external granule layer and mitosis essential, and its function is only limited to the external granule layer.