Abstract: By analysis of damdeformation observation data and structure stability calculation of Zhongqian reservoir dam, combined with operation management, appraisal was got that the dam construction quality was poor, construction speed was too fast, and this was the main reason for large deformation and cracks. The possibility of crack at the two end of the damand damsection 0+037 was high. The anti- slide stability of upstreamslope did not meet with the criterion.