Abstract: To protect patents in outer space, the key is domestic recognition and protection of such patents. International law does not hinder nations to protec t patents in outer space, what's more, it has provided the international protect ion of patents in outer space with an already existing institution. In the speci fic field of outer space law, some norms provide more detailed help for the prot ection of patents in outer space. However, the common heritage principle might b e interpreted to be an obstacle to the protection of patents in outer space, whi ch is heavily relied upon by those nations without space-faring capabilty when arguing against outer space patents protection. In fact, the real obstacle comes from the interest consideration of nation without space-faring capability.