Structural properties in spinel oxide Fe 1−x Mn x V 2 O 4 for x ≤ 0.4 have been studied using synchrotron powder diffraction experiments. The successive structural phase transitions similar to those observed in FeV 2 O 4 are observed for x = 0.1. Whereas, the only lattice distortion of cubic-to-tetragonal (c > a) is observed for x = 0.3 and 0.4. Furthermore, we have also measured the magnetization and heat capacity. The results indicate that the temperatures of magnetic phase transitions at ferrimagnetic and non-collinear ferrimagnetic order for x ≤ 0.2 correspond to those of structural transitions of orthorhombic and tetragonal (c > a), respectively. On the other hand, the temperatures of ferrimagnetic phase transition for x = 0.3 and 0.4 are consistent with those of structural transition of a cubic-totetragonal phase (c > a). These results are discussed in terms of orbital state of Fe 2+ and V 3+ ions considering the Jahn-Teller effects and spin-orbit coupling.