In the Ms8.0 Wenchuan earthquake on 12th May 2008, a large number of primary and secondary school buildings were seriously damaged. Therefore, considerable attentions have been paid to earthquake resistance capacity of school facilities and some relevant national codes in China have been updated after earthquake. Recently, many approaches to seismic retrofit of school buildings have been proposed and applied. The focus of this paper is on application of energy dissipation technology to C-category frame structure of school buildings retrofitting, with the objective of increasing one grade of precautionary intensity, while the C-category buildings are designed in conformity with China’s code for seismic design of buildings (GB 50011-2001). Since the seismic precautionary classification of school buildings has been changed from standard precautionary category to major precautionary category, the structural ductility requirements are stricter with the increase of seismic precautionary intensity. Thus, this paper presents the retrofitting difficulties in C-category frame structure of school buildings for the restriction of ductility requirements, and also explores how to apply energy dissipation technology to seismic retrofit of such buildings for achieving expected retrofitting objective and reducing heavy strengthening tasks. In the end, a retrofitting example of C-category frame structure of school building is cited to demonstrate the feasibility of energy-dissipating retrofit method. The analysis results indicate that energy dissipation technology can be well applied to C-category frame structure of school buildings retrofitting for increasing one grade of precautionary intensity.