Inthispaper,standardandeconomicalcascadicmultigridmethodsareconsideredforsolvingthealgebraicsystemsresultingfromthemortarfiniteelementmethods.Bothcascadicmultigridmethodsdonotneedfullellipticregularity,sotheycanbeusedtotacklemoregeneralellipticproblems.Numericalexperimentsarereportedtosupportourtheory.