Based on extensive field research in China during 2005–2010, this article aims to explore the determinants of unionization in the Chinese context. We find that managerial strategies toward union organizing and functioning have been critical in determining unionization outcomes in Chinese enterprises. While various environment pressures may impose critical constraints on these strategies, managerial industrial relations ideologies are central in shaping these strategies when environment pressures barely exist or are bearable by management. Our study makes the first effort in exploring industrial relations ideologies in China and contributes to better understanding of unionization in the Chinese workplace.