Abstract: Fengman dam is a concrete gravity dam in cold area, which is similar with Shuifeng dam in aspects as dam height, length and type. The overflow sections of the two dams had been rehabilitated because of freeze-thaw and frost heave destruction. After rehabilitation, Shuifeng dam has been in safe operation more than 50 years, while some dam sections of Fengman dam have been destructed again by freeze-thaw and frost heave which exerted bad influence on flood discharge structures. This paper analysed the cause reasons, for discussion.