Abstract: Leakage of the radial gate, cracking and seepage of guide plate concrete at Shenwo reservoir was found not long after construction. As known that side guide plate, water seal, improper size of gate and gate operation track may cause uneven compression of water seal which will finally cause the seepage of gate. The main difficulty is the operation track survey and problem detection. By two-year construction of the gate side guide plate at Shenwo reservoir, diagnosis and construction measures were summarized to deal with this problem. This paper introduced the experience, for reference.