We report on the growth of and the modified ferrimagnetism in DO22-structured Mn3Ga thin films epitaxially grown on GaSb(001) substrate by using molecular beam epitaxy. We have observed that the magnetic properties strongly depend on the growth temperature. The net magnetic moments of the Mn3Ga films grown at 30 °C and 200 °C are 0.23 µB/Mn and 0.75 µB/Mn atom, respectively. The as-studied Mn3Ga film is found to exhibit a relatively small coercivity around 400 Oe, which differs greatly from the hard magnetic properties of bulk Mn3Ga.