Notch signaling pathway has an important role in the development of multi-tissue and multi-organ, especially in the regulation of the nervous system development in animals while RBP-Jκ is a key molecular in the Notch signaling pathway. RAM7, which is an interactive protein with RBP-Jκ, was found by the technique of yeast two-hybrid recently. In this study a C-terminal 60 kD polypeptide fragment of RAM7 was expressed and the specific polyclonal antibodies were raised against this fragment. The distribution mapping of RAM7 was detected in the nervous system of mouse by immunohistochemistry. The results displayed that the RAM7-immunoreactive neurons were throughout the central nervous system and the immunostaining structures mainly situated in the nuclei of neurons. In the regions, such as caudate putamen, paraventricular thalamic nucleus, paraventricular hypothalamic nucleus, periventricular nucleus, there were a considerable fine staining nerve fibers, but no nucleus-staining neurons. Quite many cytoplasm-staining neurons and glia were limited in ventricular and subventricular regions. But it is still unknown what the physiological function of RAM7 is and why it is distributed like this in the nervous system in mouse.