Abstract: The key point to the safety assessment of concrete face rockfill dams is the effective layout of seepage monitoring facilities and the collection and analysis of monitoring data. Through the analysis of the dam monitoring data collected during the trial operation of Xianlin Reservoir, the seepage variation laws of the dam foundation, dam and other key parts are summarized. The influences of rainfall and other factors on the water level at the measuring points are analyzed. The comprehensive monitoring data show that the dam foundation and dam seepage control system works well at both sides. The layout of the seepage monitoring facilities of Xianlin Reservoir is reasonable and effective.