Live teaching is one of two basic e-Learning modes. In this paper, a novel interactive live teaching system named SkyClass based on the hybrid platform of satellite and ground 1P network is modeled, SkyClass uses receive-only satellite links for live lecture broadcasting, and ground network to realize outside interaction. Three key issues of SkyClass, live lecture fieM broadcasting over the hybrid of satellite and ground IP, large scale communications and management, live lecture field recording and stream courseware generating automatically, are discussed SkyClass has already been implemented and applied on the platform of ASIA-2R satellite and ChinaNet and CERNET (China Educational and Research Network) in the distance learning project of west area of China since Sept. 2003, it was proved that not only can SkyClass support large scale (more than 2500 remote sites) live lecture broadcasting and outside interaction, but also shows good extendibilitt, reliability, and easy o fuse.