Background: Both teacher support and math attitudes have been identified as associated with math anxiety in primary school children. However, little is known about how they are interrelated longitudinally. Aims: The study was designed to examine the associations among perceived teacher support, math attitudes, and math anxiety in Chinese primary school students. Sample: The sample included 1802 students (56.16% boys) initially in the third and fourth grades in two public schools in China. Methods: A three-year cross-lagged panel design was conducted to examine the associations among perceived teacher support, math attitudes, and math anxiety. Moreover, a multigroup analysis was used to examine whether the associations varied by gender. Results: There were reciprocal associations over time between math attitudes and math anxiety. Meanwhile, both math attitudes and math anxiety significantly predicted perceived teacher support one year later, but not vice versa. Further, the association between T1 math anxiety and T3 perceived teacher support was mediated by T2 math attitudes; the association between T1 math attitudes and T3 perceived teacher support, on the other hand, was mediated by T2 math anxiety. Moreover, there were no significant gender differences in these associations. Conclusions: Math anxiety and math attitudes objectively affected each other, and both of them significantly predicted later perceived teacher support, but not vice versa. This study demonstrates that children are not merely passive recipients of environmental influences and offers theoretical guidance for intervention practices that aim to reduce the risk of math anxiety.