Abstract: So far dams of 96 hydropower stations have been performed in the first round periodic inspection since the rules of periodic inspection and assessment have been implemented in 1987. A series of repair measures have been taken to eliminate the pitfalls and defects at the same time to make dams exert much function in flood control and generation. Looking forward to the first ten years of 21st century, we are facing three aspects of disaster mechanism of dams, countermeasures, underwater repair and preventive measures. The status of dam safety of hydropower stations will be further improved by our effort.?