How did one become an astronomer in imperial China? Where did one start? What texts did would-be astronomers study, and what criteria did they have to meet? Combining the regulation of the Yuan (1271–1368) Bureau of Astronomy with biographies of astronomers who worked in different sections of the Bureau, this paper explores the physical, technical, and literary skills required for this profession in late medieval China. It underscores the pivotal role of family in training astronomers and offers fresh insights into the relationship between bureaucracy and science in imperial China.