Molecular-beam epitaxial growth and characterization of GaSb films with high concentration of Mn (several percents) are presented. The result shows that almost all Mn atoms in GaSb forms MnSb clusters at normal growth temperature (similar to 560 degrees C), and that low growth temperature (similar to 250 degrees C) suppresses the formation of MnSb and a few tens of percent of Mn are incorporated in the host GaSb.