A ferrimagnetic ordering with a magnetic moment of 0.66 μB/Mn has been obtained in an epitaxial Mn thin film on a BaTiO3 substrate. The structural deformation of the Mn film was modulated by thermal strain due to the thermal expansion difference between the Mn film and BaTiO3. Three jumps in the resistivity at 185, 290, and 390 K and two jumps in the magnetization at 290 and 365 K in the Mn film correspond to structural phase transitions of BaTiO3 at below 400 K. These results indicate the feasibility of tuning the electrical and magnetic properties of the Mn film by modulating the interface strain via phase changes of BaTiO3.