Abstract: Gutianxi Ⅲ dam was initially built in Aug,1958. Due to operating for 40 years, it has many problems including part of curtain in dam foundation losing effectiveness, the integrality of facing concrete being weakened in some extent, stability against sliding of some monoliths and lateral stability of counterfort retaining wall falling short of requirement of specifications in force. This article introduced the overall rehabilitation on this dam and its effect.?