Diluted magnetic semiconductor film GaMnN was grown on sapphire (α-Al2O3) substrate using biscyclopentyldienyl manganese (Cp2Mn), N2 and TEGa by electron cyclotron resonance-plasma enhanced metal organic chemical vapor deposition(ECR-PEMOCVD) . The crystal structure and surface topography of the GaMnN films were characterized by RHEED, XRD and AFM. GaMnN films exhibit good (0002) preferred orientation, showing the films are inclined to c-axis growth and retain good wurtzite structure. The surface topography of GaMnN film is composed of many submicron grains piled in the consistent orientation. The magnetism of films is characterized by SQUID. SQUID shows that the film is ferromagnetic, which comes probably only from the ternary phase GaMnN and the Curie temperature of GaMnN film is higher than 350 K. Moreover, higher Mn concentration can enhance the Curie temperature of the film.