Perfectionism is widely recognised as a key factor in students' learning experiences, but such evidence is primarily derived from cross-sectional studies testing unidirectional links. To fill in the gap, our study used a longitudinal design and made the initial attempt to examine the bi-directional links between two types of perfectionism (personal standards and concerns over mistakes), two types of academic motivation (intrinsic and extrinsic motivation), and academic engagement. Results from the cross-lagged panel analysis among Chinese university students found that personal standards and intrinsic motivation were positively and reciprocally related. Another reciprocity was revealed: intrinsic motivation positively predicted later extrinsic motivation, while extrinsic motivation negatively predicted later intrinsic motivation. Besides, our study revealed several unidirectional links: intrinsic motivation positively predicted later academic engagement, extrinsic motivation positively predicted later concerns over mistakes, and academic engagement negatively predicted later concerns over mistakes.