We grew epitaxial CoMn2O4 and Co2MnO4 thin films on Nbdoped (0.1 wt.%) SrTiO3(100) singlecrystal substrates by using pulsed laser deposition and studied how the growth temperature affected their crystal structures and surface morphologies. For Co2MnO4, increasing the growth temperature induced no significant changes except for an enlarged grain size. In contrast for CoMn2O4, increasing the growth temperature caused its surface morphology to evolve from spherical grains to rectangular nanorods; additionally, X-ray diffraction showed that these rectangular nanorod grains scattered to domains with different crystal orientations. We attribute this rectangular nanorod pattern to self-assembled domains originating from Jahn-Teller distortions and film-substrate lattice mismatch