Abstract:High sulfate-resistant cement grout was used for reinforcing the fractured zone in the flexural core of the dam foundation of Xiangjiaba Hydropower Station. Since the depth of grouting holes was more than 150m, higher requirements were specified for the grout than those used in the conventional process in terms of the stability, groutability, wall reinforcement, separation, initial setting time, strength of stone body, etc. during drilling and grouting construction. Therefore, research has been carried out to compare the high sulfate resistance cement added with the retarded water reducer and the modified the high sulfate resistance cementto deal with the reinforcement of the dam foundation of Xiangjiaba Hydropower Station with grouting treatment, and preliminary results have been achieved . It is found that the stability, groutability, wall reinforcement, separation, initial setting time and stone strength of the modified high sulfate-resistant cement slurry with sodium hexametaphosphate instead of the retarded superplasticizer as the retarder and dispersant are better than those of the high sulfate-resistant cement slurry with the retarded superplasticizer, and its performance is better matched with the process.