Abstract: Dashankou dam safety periodic inspection began in Sept.of 1999. It not only reviewed project level, flood control standard, engineering geological conditions, stability of dam body stress, but also rechecked construction quantify. This paper also analyzed the cause of gravity buttress cracks and its effects, seepage at foundation, dam deformation,dam operation as well. In combination with the filed inspection, the expert team has finished the periodic inspection. The dam is assessed as normal dam.?