Abstract: Qingcaosha reservoir is located in the entrance of Yangtze river. The body and foundation of levee is con〉 posed of a large number of sand and silt. To ensure the safety of tile levee and master the levee seepage law, it needs the special researching on seepage characteristics of levee. The seepage testing of levee was respectively done in construction period of 2007 and operating period of 2010. Seepage parameter of the two periods was compared, and the seepage parameter of operating period was analyzed using significance tests of mathematical statistics. It supplied effective data for the studying of seepage deformation.