The notion of relative log de Rham-Witt complex, which is the log version of relative de Rham-Witt complex of Langer-Zink, is defined by Matsuue. In this talk, we give the comparison theorem between relative log de Rham-Witt cohomology and relative log crystalline cohomology for log smooth saturated morphism of fs log schemes satisfying certain condition on which p is nilpotent. Our result generalizes most of the previously known results by Illusie, Hyodo-Kato, Langer-Zink and Matsuue.