Teacher noticing of student mathematics thinking, an essential professional competency, has not been sufficiently investigated in China. In this paper, based on four video clips, we combined the frameworks of Stockero et al. and Jacobs to analyze the characteristics and changes of 19 prospective teachers’ (PTs) noticing under the intervention of the course “Mathematics Teaching Theory in Middle School.” The results showed that (1) the agent of noticing shifted from teachers and mathematical content to students; (2) the percentage of noticing to content with mathematical characteristics remained high, and that of noticing to general math increased significantly after the intervention; and (3) the percentages of noticing to analyzing student math learning and math interaction noticeably increased. Moreover, from select PT interviews (four in total) and facilitator reflections, we concluded four potential strategies for improving interventions to enhance PT noticing: enriching video resources, refining the task requirements, specifying teaching evaluations, and optimizing course implementation.