Abstract: Dongkeng reservoir dam was originally designed as a concrete faced rock-fill dam which was 42.0 m high. As no mechanical compaction used, the void ratio of rock fill was as high as 40%. Since operation, problems occurred such as large displacement, going-on settlement, serious cracking of concrete slabs, severe leakage and et al. Aiming at the problems, namely the existing dam leakage, deformation, low strength of the original rockfill, the treatment scheme of adding a main rockfill zone upstream the original rockfill and new construction of impervious reinforced concrete slab was adopted, which diverted most of the water load to the newly constructed rockfill zone upstream the dam axis, resulting a decrease of water load over the original rock-fill zone. After rehabilitation, deformation and seepage amount of Dongkeng dam were small and good effect was achieved, worthy reference.