In the first part of this article, the author tries to clarify a set of interconnected concepts—religious plurality (diversity), pluralization, and pluralism. As a descriptive concept for sociological theorizing, social pluralism is further differentiated into legal, civic and cultural arrangements. Modern pluralization may have started accidentally in the United States of America, but it has become a general trend in the world. In the second part, the author argues that the predominant type of Church—State relationship in the world today is neither monopoly nor pluralism, but oligopoly. More importantly, the theoretical propositions based on the studies of monopoly-pluralism are not applicable without substantial modification to explain oligopoly dynamics. The China case shows that in oligopoly, increased religious regulation leads not necessarily to religious decline, but to triple religious markets: the red market (legal), black market (illegal) and grey market (both legal and illegal or neither legal nor illegal).