The article is devoted to the problem of diversity management in world cities. One of the specific characteristics of these territorial and political entities in the globalizing world is their magnetism for thousands of migrants searching for better quality of life, self-realization, and safety. Historically the cities were population and activities’ concentration centres for long centuries. So, the ethnic and cultural diversity is the long-lasting problem to be solved for keeping peace and continuing development. The diversity management for largest Russian cities – Moscow and Saint Petersburg – is as important as for other global cities of the world.