The DMS GaMnN film with certain concentration of Mn and good crystal qualities has been successfully grown on the substrate of sapphire (α-Al2O3) by ECR-PEMOCVD. The graphs of RHEED presented a clear spot-like lattice and the surface was not very glossy, which showed that the GaMnN film was single crystalline and its growth model was three -dimensional island. XRD analysis showed that the film was hexagonal structure with c -Axis oriented and the crystallinity was very well. The AFM test result showed that the GaMnN films were composed of many submicron grains with the same orientation. SQUID(superconducting quantum interference device) measurement showed an apparent ferromagnetic hysteresis at room temperature, and the Curie temperature of the film was about 400k.