This paper provides a historiographical periodization of China's Long 1980s (1978-1992) by conceptualizing its political and intellectual contexts and illustrating the reformism-conservatism dichotomy across key events throughout this period. The identification of China's Long 1980s not only illuminates China's policy trajectories and ideological landscape back then and ever since but also enriches the global scholarship of modernity, Marxism and 20th-century communist experiences.