The use of geosynthetic clay liners (GCLs) in waste disposal facilities is becoming more common. However, the bentonite component of the GCLs is known to undergo reduction of shear strength upon hydration. As a result, placing GCLs in final covers on slope raises question about the stability. Laboratory tests were performed to study the shearing behavior of GCLs. In addition, finite element computations were carried out to evaluate the possible long-term deformation of the final cov, rs on slopes containing GCLs. The computations showed that with the use of geosynthetic reinforcements, not only the stability of the final covers can be increased but the deformation can be greatly reduced. In addition, based on the result of computations, a modified limit equilibrium method was proposed for final cover design.