Ferromagnetic GaMnSb has been fabricated by a feasible and low expense method through thermal diffusion of vacuum evaporated Mn on the surface of GaSb. With the introduction of Mn, the concentration of hole carriers increases significantly. The existence of Mn has not lead to obvious appearance of secondary phase, like MnSb, confirmed by X-ray diffraction. A shifted Raman peak clearly indicates the doping effect of Mn. We have also observed an M-H hysteresis loop at 10 K by superconducting quantum interference device. The Curie temperature of GaMnSb in our sample is about 30 K. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.