To appear in The Fabulous Destiny of Galaxies: Bridging Past and Present, conference held in Marseille, June 2005 ; We present FUSE observations of molecular hydrogen in the circumstellar environment of a sample of Herbig Ae/Be stars spanning the spectral range A5-B2. Our analysis demonstrates that the excitation of H2 is clearly different around HAeBes than in the interstellar medium, and that the characteristics of H2 around Herbig Ae and Be stars give evidences for several mechanisms of excitation.