Geosynthetics play a very important role in application to waste landfills. They can be used as surface layer, protective layer, drainage layer, barrier layer, as well as for gas collection. This paper introduces how geosynthetics are applied as the components of the cover and the liner systems of waste landfills. Some consideration and important issues are also mentioned for material selection, designing, and construction. In addition, the characteristics of geomembranes are described as well.