Abstract: The subject of this research is the relevant issues of correlation between the constitutional principle of ideological diversity and the extensively discussed within the Russian society question of establishment of the Russian national idea. The authors meticulously review various doctrinal approaches towards interpreting the constitutional principle of ideological diversity, as well as give special attention to the characteristic of the distinctive signs of ideology and national idea. It is noted that the ideology expresses the interests of separate social groups, is applicable to the sphere of limited, specific; national idea is characterized by universality and ubiquity, as well as manifests as a unifying social beginning that contains the common value bases of social life. The authors underline that in the context of the Russian history and present, the category of national idea is used in a narrow-ethnic, but broader cultural-civilizational meaning, which reflects the multinational and multiconfessional nature of the Russian society. Conclusion is made that the ideology alongside the national idea are not included into the subject of legal regulation, but rather suggest a continuously renewing dialogue, search process of the historically justified optimal combination of interests of the various social groups for the purpose of reproducing the social world.