Abstract: The idea of ruling-by-law in western countries,which was originated in Ancient Greece and Rome,has developed into two legal systems of constitution and democratic republic,with America being the representative of the later.Under legal circumstances,the idea of ruling-by-law is a major supplement to the idea of ruling-by-moral,which is of value for the implement of ruling-by-law and ruling-by moral in our country.

Key words: ruling-by-law, ruling-by moral, law, moral