Abstract：The engineering geologic condition is complex in Qingjiang Shuibuga Hydropower Station. The concrete slab thickness is 0.6 to 1.2 m and the width is 6 to 8 m，so that the weight of the cover on grout layer is light. The antiseepage standard is quite high，impervious distance is long，and grouting amount is big. According to the practical condition，testing of curtain grouting in site is carried out at region A，which is representative of the whole engineering condition. Deformation is recorded with automatic measuring system. The best arrangement pattern of grouting holes is given based on analysis on test data. 525# Portland cement is adopted and water-cement ratio is divided into five grades of 2∶1，1∶1，0.8∶1，0.6∶1 and 0.5∶1，which are proper for grouting of small water-cement ratio and high pressure. Big upward deformation may occur，and control measures are given to such case.
