Objective  To investigated the spatial and temporal expression of Atoh1 mRNA and protein level during the cerebellar development.   Methods  The frozen cerebellum sections of mice at different developmental stages were used to analyze the temporal and spatial expression patterns of Atoh1 mRNA by RNA scope technique, n=3 for each group. Meanwhile, two reporter mice with different genetic modification method were utilized to analyze the   spatialand temporal expression of Atoh1 at the protein level by immunofluorescence staining, n=3 for each group.  Results  Atoh1 mRNA was highly expressed in the embryonic cerebellar rhombic lip (RL) and the external granule layer (EGL). At the protein level, staining result of Atoh1-3*V5-P2A-tdTomato/+ knockin mice showed that Atoh1 was mainly expressed in the RL and the outer layer of the proliferative EGL. Atoh1-Cre;tdTomato/+   transgenic reporter mice showed that tdTomato positive cells were highly expressed in the EGL and the inner granule cell layer (IGL) during the whole granule cells   development.   Conclusion  During cerebellar development, Atoh1 mRNA and protein were highly expressed in the embryonic rhombic lip and postnatal external granule layer.    However, at the protein level, the expression of Atoh1 in the rhombic lip and external granule layer were different between knockin mice and transgenic mice.